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A 

SYSTEM  OF  ANATOMY 


FOR  THE  USE  OF 


STUDENTS  OF  MEDICINE. 


BY  CASPAR  WISTAR,  M.  D. 

PROFESSOR  OF  ANATOMY 

IN  THE 

UNIVERSITY  OF  PENNSYLVANIA. 


VOLUME  II. 


PHILADELPHIA: 

PUBLISHED  BY  THOMAS  DOBSON  AT  THE  STONE  HOUSE, 
No.  41,  SOUTH  SECOND  STREET. 

William  Fry,  Printer. 

1814. 


Ui\Sb^< 

V ' CL> 


District  of  Pennsylvania,  to  wit: 

*»•*»*»****  BE  IT  REMEMBERED,  That  on  the  twenty-third 
I SEAL.  * day  of  February,  in  the  thirty-eighth  year  of  the  Inde- 
• *«»*«**•*»  pendence  of  the  United  States  of  America,  A D.  1814, 
Thomas  Dobson,  of  the  said  district,  hatli  deposited  in  this  office  the 
title  of  a book,  the  right  whereof  he  claims  as  proprietor,  in  the  words 
following,  to  wit: 

“ A System  of  Anatomy  for  the  use  of  Students  of  Medicine.  By 
“ Caspar  Wistar,  M.  D.  Professor  of  Anatomy  in  the  University 
“ of  Pennsylvania.  Vo'ume  II.” 

In  conformity  to  the  act  ofthe  congress  of  the  United  States,  intitu- 
led, “ An  act  for  the  encouragement  of  learning,  by  securing  the  copies 
of  maps,  charts  and  books,  to  the  authors  and  proprietors  of  such  copies 
during  the  times  therein  mentioned.” — And  also  to  the  act,  entitled, 
“ An  act  supplementary  to  an  act,  entitled  “ An  act  for  the  encourage- 
ment of  learning,  by  securing  the  copies  of  maps,  charts,  and  books,  to 
the  authors  and  proprietors  of  such  copies  during  the  times  therein 
mentioned,”  and  extending  the  benefits  thereof  to  the  arts  of  designing, 
engraving,  and  etching  historical  and  other  prints.” 

D.  CALDWELL, 

Clerk  of  the  District  of  Pennsylvania* 


CONTENTS  OF  VOL.  II. 


PART  VI. 

OF  THE  NOSE— THE  MOUTH— AND  THE  THROAT, 


CHAPTER  I. 

Of  the  Nose. 

SECTION  I. 

\ Page 

Of  the  External  Nose  .....  2 

SECTION  II. 

Of  the  Cavities  of  the  Nose  .....  5 

CHAPTER  II. 

Of  the  Mouth  and  the  Salivary  Glands. 

Of  the  Mouth,  ...  . ...14 

Of  the  Salivary  Glands  ...  5T5 


CHAPTER  III. 

Of  the  Throat. 

SECTION  I. 

Of  the  Isthmus  of  the  Fauces  - - * . 29 

SECTION  II. 

Of  the  Larynx  - - - - 31 

Of  the  Thyroid  Gland  - ....  37 

SECTION  III. 

Of  th#  Pharynx  * - 38 


IV 


CONTENTS. 


Page 

PART  VII. 

OF  THE  THORAX. 

CHAPTER  I. 

Of  the  general  Cavity  of  the  Thorax. 

SECTION  I. 

Of  the  Form  of  the  Cavity  of  the  Thorax  44 

SECTION  II. 

Of  the  Arrangement  of  the  Pleurae  45 

Preparation  of  the  Thorax  - - - - 47 

CHAPTER  II. 

Of  the  Heart  and  the  Pericardium , and  the  Great  Vessels  con « 


nected  with  the  Heart. 

SECTION  I. 

Of  the  Pericardium  ------  49 

SECTION  II. 

Of  the  Heart  - --  - . - -50 

SECTION  III. 

Of  the  Aorta,  the  Pulmonary  Artery  and  Veins,  and  the 
Venae  Cavse  at  their  commencement  59 

CHAPTER  III. 

Of  the  Trachea  and  Lungs. 

SECTION  I. 

Of  the  Trachea  - --  --  ..  62 

The  Black  Glands  on  the  Bronchiae  64 

SECTION  II. 

Of  the  Lungs  -------  65 

Thorax  of  the  Foetus  ------  69 

Physiological  Observations,  &c.  - - - - 71 


PART  VIII. 

OF  THE  ABDOMEN. 

CHAPTER  I. 

A general  view  of  the  Abdomen  and  Pelvis , and  their  Contents ; 
with  an  Account  of  the  Peritoneum. 

SECTION  I. 

Construction  of  the  Abdomen  83 

Contents  of  the  Abdomen  86 

SECTION  II. 


Of  the  Peritoneum 


91 


CONTENTS, 


v 


CHAPTER  II. 

Of  the  IE.sofihagua,  the  Stomach , and  the  Intestines. 
SECTION  I. 

Of  the  (Esophagus  - .... 

SECTION  II. 

Of  the  Stomach  ..... 
Of  the  Gastric  Liquor  .... 

SECTION  III. 

Of  the  Intestines  .... 

Division  of  the  Intestines  ..... 

The  Small  Intestines  ...  - 

The  Duodenum  ..... 
Jejunum  and  Ileon  ...  ... 

The  Mesentery  - - ... 

Of  the  Great  Intestines  - ... 

The  Caecum  and  Colon  ... 

The  Rectum  ..... 

The  Omentum  ..... 

CHAPTER  III. 

Of  the  Liver , the  Pancreas , and  the  Sfileen. 
SECTION  I. 

Of  the  Liver  ..... 

SECTION  II. 

Of  the  Pancreas  - - ... 

SECTION  III. 

Of  the  Spleen  ..... 
CHAPTER  IV. 

Of  the  Urinary  Organs , and  the  Glandules  Renales. 
SECTION  I. 

Of  the  Glandulae  Renales  ... 

SECTION  II. 

Of  the  Kidneys  and  Ureters  - 

SECTION  III. 

Of  the  Urinary  Bladder  .... 
CHAPTER  V. 

Of  the  Male  Organs  of  Generation. 
SECTION  I. 

Of  the  Testicles  and  their  Appendages 


Tagt 

95 

97 

103 

106 

111 

112 

113 

114 

116 

119 

120 

124 

126 

129 

144 

146 

156 

1 58 

164 

173 


VI 


CONTENTS, 


SECTION  II. 

Of  the  Vesiculse  Seminales  and  the  Prostate  Gland 
SECTION  III. 

Of  the  Penis  - 


CHAPTER  VI. 

Of  the  Female  Organs  of  Generation. 
SECTION  I. 

Of  the  External  Parts  of  Generation 


SECTION  II. 


Of  the  Vagina  .... 

SECTION  III. 

Of  the  Uterus,  the  Ovaries,  and  their  Appendages 


SECTION  IV. 

Of  the  Bladder  and  Urethra 


I?age 

183 

186 


200 

2Q3 

205 


213 


PART  IX. 

OF  THE  BLOODVESSELS. 

CHAPTER  I. 

Of  the  General  Structure  and  arrangement  of  the  Bloodvessels . 
SECTION  I. 

Of  the  Arteries  - - - 22 7 

SECTION  II. 

Of  the  Veins  .....  235 

CHAPTER  II. 

A Particular  Account  of  the  Distribution  of  the  Arteries. 
SECTION  I. 

Of  the  Aorta,  or  the  Great  Trunk  of  the  Arterial  System  238 
SECTION  II. 

Of  the  Branches  which  go  off  from  the  Arch  of  the  Aorta  240 
The  Carotid  Arteries  - - - - - 241- 

The  Subclavian  Arteries  .....  258 

SECTION  III. 

Of  the  Branches  which  go  off  between  the  Arch  and  the 
Great  Bifurcation  of  the  Aorta  ....  274 

Bronchial  Arteries  ......  ibid. 

CEsophageal  Arteries  - ibid. 

Fnferior  Intercostals  - - * - - 7 275 


CONTENTS. 


vii 


Phrenic  Arteries 
Cceliac  Artery  - 
Superior  Mesenteric  Artery 
Inferior  Mesenteric  Artery 
Emulgent  or  Renal  Arteries 
Capsular  and  Adipose  Arteries 
Spermatic  Arteries 
Lumbar  Arteries 
Middle  Sacral  Artery 


Page 

277 

ibid. 

280 

282 

283 
ibid. 

284 

285 
ibid , 


SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the  Great 
Bifurcation  of  the  Aorta  ----- 
The  Primitive  Iliac  Arteries  - - - - 

Internal  Iliac  Arteries  ------ 

External  Iliac  Arteries  - 

Femoral  Artery  ------- 

Arteries  of  the  Leg  - 


285 
ibid. 

286 

291 

292 
295 


CHAPTER  III. 

Of  the  particular  Distribution  of  the  Veins. 


SECTION  I. 

Of  the  Superior,  or  Descending  Vena  Cava,  and  the  Veins 
which  communicate  with  it  - - 303 

Vena  Azygos  - - 304 

Internal  Jugular  Veins - 307 

External  Jugular  Veins  -----  309 

Subclavian  Vein 310 


SECTION  II. 

Of  the  Inferior  Vena  Cava,  and  the  Veins  connected  with 


it 313 

Hepatic  Veins  ...  - . - - . 314 

Vena  Portarum  ------  ibid. 

Emulgent  or  Renal  Veins  - - - - - 315 

Spermatic  Veins  -------  316 

Lumbar  Veins  -------  ibid. 

Middle  Sacral  Vein  ------  ibid. 

Primitive  Iliac  Veins  ------  ibid. 

Internal  Iliac  Veins  - - - - - - 31f 

External  iliac  .-  ....  318 

Femoral  Vein  - ...  ibid. 

Instances  of  Peculiar  Arrangement  of  the  Veins  - 320* 

Of  the  Pulmonary  Artery  and  Veins  - - 331 


via 


CONTENTS 


PART  X. 

OF  THE  NERVES. 

Nerves  of  the  Brain 

Of  the  Cervical  Nerves 

Nerves  of  the  Diaphragm 

Brachial  Plexus 

Nerves  of  the  Arm 

The  Dorsal  Nerves 

Of  the  Lumbar  Nerves 

The  Sacral  Nerves 

Sciatic  Plexus  - 

Great  Sciatic  Nerve 

Great  Sympathetic  Nerve 

Nerves  of  the  Heart 

Nerves  of  the  Abdominal  Viscera 


Page 


328 

349 

351 

352 

353 
357 
359 

362 

363 

364 
367 
369 
374 


PART  XI. 

OF  THE  ABSORBENT  VESSELS 

CHAPTER  I. 

Of  the  Absorbents  of  the  Lower  Extremities— the  Abdomen  and 
the  Thorax. 

SECTION  I. 

The  Absorbents  of  the  Lower  Extremities  - 382 

SECTION  II. 

The  Absorbents  of  the  Abdomen  and  Thorax  - 387 

CHAPTER  II. 

Of  the  Absorbents  of  the  Head  and  JVecf,  of  the  Upper  Extre- 
mities, and  the  Upper  Part  of  the  Trunk  of  the  Body. 

SECTION  I. 

Of  the  Absorbents  of  the  Head  and  Neck  - - 397 

SECTION  II. 

Of  the  Absorbents  of  the  Arm,  and  Upper  Part  of  the 
Trunk  - 398 


SYSTEM  OF  ANATOMY. 


PAET  YI. 

op  the  nose:  the  mouth:  and  the  throat. 


CHAPTER  I. 

OF  THE  NOSE. 

T HE  prominent  part  of  the  face,  to  which  the  word  nose 
is  exclusively  applied  in  ordinary  language,  is  the  anterior 
covering  of  two  cavities  which  contain  the  organ  of  smell- 
ing. 

These  cavities  are  formed  principally  by  the  upper  max- 
illary and  palate  bones;  and,  therefore,  to  acquire  a com- 
plete idea  of  them,  it  is  necessary  to  study  these  bones,  as 
well  as  the  os  ethmoides,  the  vomer,  and  the  ossa  spongi- 
osa  inferiora,  which  are  likewise  concerned  in  their  forma- 
tion. 

In  addition  to  the  description  of  these  bones,  in  the  ac- 
count of  the  bones  of  the  head,  it  will  be  useful  to  study 
the  description  of  the  cavities  of  the  nose  which  follows  it. 
See  vol.  I,  page  56. 

After  thus  acquiring  a knowledge  of  the  bony  structure, 
the  student  will  be  prepared  for  a description  of  the  softer 
parts. 

VOL.  II. 


A 


Q 


SECTION  I. 

Of  the  External  Nose. 

THE  superior  part  of  the  nose  is  formed  by  the  ossa 
nasi,  and  the  nasal  processes  of  the  upper  maxillary  bones, 
which  have  been  already  described;  (see  vol.  I,  pages  34 — 
37.)  but  the  inferior  part,  which  is  composed  principally  of 
cartilages,  is  much  more  complex  in  its  structure. 

The  orifice,  formed  by  the  upper  maxillary  and  nasal 
bones,  is  divided  by  a cartilaginous  plate,  which  is  the  an- 
terior and  inferior  part  of  the  septum,  or  partition  between 
the  two  cavities  of  the  nose.  The  anterior  edge  of  this 
plate  projects  beyond  the  orifice  in  the  bones,  and  conti- 
nues in  the  direction  of  the  suture  between  the  ossa  nasi. 
This  edge  forms  an  angle  with  the  lower  edge  of  the  same 
cartilage,  which  continues  from  it,  in  a horizontal  direction, 
until  it  reaches  the  lower  part  of  the  orifice  of  the  nose,  at 
the  junction  of  the  palatine  processes  of  the  upper  maxilla- 
ry hones;  where  a bony  prominence  is  formed,  to  which  it 
is  firmly  united.  The  upper  part  of  the  anterior  edge  of 
this  cartilage,  which  is  in  contact  with  the  ossa  nasi,  is  flat, 
and  is  continued  into  two  lateral  portions  that  are  extend- 
ed from  it,  one  on  each  side,  and  form  a part  of  the  nose: 
these  lateral  portions  are  sometimes  spoken  of  as  distinct 
cartilages;  but  they  are  really  continuations  of  the  middle 
portion  or  septum. 

Below  the  lower  edge  of  these  lateral  portions  are  situ- 
ated the  cartilages  which  form  the  orifices  of  the  nose,  or 
the  nostrils.  Of  these,  there  is  one  of  considerable  size, 
and  several  small  fragments,  on  each  side  of  the  septum. 
Each  of  the  larger  cartilages  forms  a portion  of  an  oval 


3 


Of  the  Nose. 

ring,  which  is  placed  obliquely  on  the  side  of  the  septum: 
so  that  the  extremity  of  the  oval  points  downward  and  for- 
ward,  while  the  middle  part  of  the  oval  is  directed  up- 
wards and  backwards.  The  sides  of  this  cartilage  are  flat, 
and  unequal  in  breadth.  The  narrowest  side  is  internal, 
and  projects  lower  down  than  the  cartilaginous  septum;  so 
that  it  is  applied  to  its  fellow  of  the  other  nostril.  The  ex- 
ternal side  is  broader,  and  continues  backward  and  up- 
ward to  a considerable  distance. 

The  upper  and  posterior  part  of  this  oval  ring  is  defi- 
cient; but  the  remainder  of  the  nostril  consists  of  several 
small  pieces  of  cartilage,  which  are  fixed  in  a ligamentous 
membrane  that  is  connected  by  each  of  its  extremities  to 
the  oval  cartilage,  and  thus  completes  the  orifice. 

The  anterior  parts  of  the  oval  cartilages  form  the  point 
of  the  nose;  and  the  ligamentous  portions,  the  alee  or 
lateral  parts  of  the  nostrils. 

When  the  external  integuments  and  muscles  are  remo- 
ved from  the  lower  portion  of  the  nose,  so  that  the  internal 
membrane  and  these  cartilages  only  remain,  the  inter- 
nal membrane  will  be  found  attached  to  the  whole  bony 
margin  of  each  orifice,  and  to  each  side  of  the  whole  ante- 
rior edge  of  the  middle  cartilage,  which  projects  beyond 
the  bones,  so  that  it  would  close  up  these  openings  of  the 
nose,  if  it  were  not  for  the  orifices  formed  by  the  oval  car- 
tilages and  the  ligament  above  described;  but  being  attach-  » 
ed  to  one  edge  only  of  these  cartilages,  the  orifice  formed 
by  them  is  complete. 

The  internal  portions  of  the  oval  cartilages  being  situ- 
ated without  the  septum,  and  applied  to  each  other,  they 
form  the  external  edge  of  the  partition  between  the  nos- 
trils, or  the  columna  nasi;  which  is  very  movable  upon 
the  edge  of  the  middle  cartilage. 


4 


Motions  of  the  Apertures , &?c. 

The  orifices  of  the  nostrils,  thus  constructed,  are  dilated 
by  that  portion  of  the  muscle,  called  Levator  Lah'ii  Superi- 
oris  Alceque  Nasi , which  is  inserted  into  the  alae  nasi. 
They  are  drawn  down  by  the  depressor  labii  superioris 
alseque  nasi.  They  are  pressed  against  the  septum  and  the 
nose  by  the  muscle  called  Compressor  Naris , which  has 
however  an  opposite  effect  when  its  upper  extremity  is 
drawn  upwards  by  those  fibres  of  the  occipito-frontalis, 
which  descend  upon  the  nose,  and  are  in  contact  with  it. 

The  end  of  the  nose  is  also  occasionally  drawn  down,  by 
some  muscular  fibres  which  descend  from  it,  on  the  septum 
of  the  nose,  to  the  orbicularis  oris:  they  are  considered  as 
a portion  of  this  muscle  by  many  anatomists,  but  were 
described  by  Albinus  as  a separate  muscle,  and  called  Na~ 
salts  Labii  Superioris. 

When  inspiration  takes  place  with  great  force,  the  alse 
nasi  would  be  pressed  against  the  septum  if  they  were  not 
drawn  out  and  dilated  bv  some  of  the  muscles  above  men- 
tioned. 


5 


SECTION  II. 

Of  the  Cavities  of  the  Nose. 

TO  the  description  of  the  osseous  parts  of  the  nasal  cavi- 
ties in  vol.  I,  page  56,  it  ought  now  to  be  added  that  the 
vacuity  in  the  anterior  part  of  the  osseous  septum  is  filled 
up  by  a cartilaginous  plate,  connected  with  the  nasal  lamella 
of  the  ethmoid  bone  above,  and  with  the  vomer  below. 
This  plate  sends  off  those  lateral  portions  already  descri- 
bed, which  form  the  cartilaginous  part  of  the  bridge  of  the 
nose. 

It  should  also  be  observed  that  at  the  back  parts  of  these 
cavities  are  two  orifices  called  the  Posterior  Pares , which 
are  formed  by  the  palate  bones,  the  vomer,  and  the  body 
of  the  sphenoidal  bone,  and  are  somewhat  oval  in  figure. 

The  nasal  cavities,  thus  constructed,  are  lined  by  a pe- 
culiar membrane,  which  is  called  pituitary  from  its  secre- 
tion of  mucus,  or  Schneiderian  after  an  anatomist  who  de- 
scribed it  with  accuracy.* 

This  membrane  is  very  thick  and  strong,  and  abounds 
with  so  many  bloodvessels,  that  in  the  living  subject  it  is 
of  a red  colour.  It  adheres  to  the  bones  and  septum  of  the 
nose  like  the  periosteum,  but  separates  from  them  more 
easily.  The  surface  which  adheres  to  the  bones  has  some 
resemblance  to  periosteum;  while  the  other  surface  is  soft, 
spongy,  and  rather  villous.  Bichat  seems  to  have  consi- 
dered this  membrane  as  formed  of  two  laminae,  viz:  peri- 
osteum, and  the  proper  mucus  membrane;  but  he  adds, 
that  it  is  almost  impossible  to  separate  them. 

It  has  been  supposed  that  many  distinct  glandular  bo- 

4 Conrad  Schneider,  a German  professor,  in  a large  work,  “ De  Ca- 
tarrh is,”  published  about  1660. 


6 


Schneiderian  Membrane. 


dies  were  to  be  seen  in  the  structure  of  this  membrane  by 
examining  the  surface  next  to  the  bones;*  but  this  opinion 
is  adopted  by  very  few  of  the  anatomists  of  the  present 
day.  The  texture  of  the  membrane  appears  to  be  uniform; 
and  on  its  surface  are  a great  number  of  follicles  of  various 
sizes,  from  which  flows  the  mucus  of  the  nose. 

These  follicles  appear  like  pits,  made  by  pushing  a pin 
obliquely  into  a surface  which  retains  the  form  of  the  im- 
pression. They  can  be  seen  very  distinctly  with  a common 
magnifying  glass  when  the  membrane  is  immersed  in  wa- 
ter, both  on  the  septum  and  on  the  opposite  surface.  They 
are  scattered  over  the  membrane  without  order  or  regu- 
larity, except  that  in  a few  places  they  occur  so  as  to  form 
lines  of  various  lengths,  from  half  an  inch  to  an  inch.  The 
largest  of  them  are  in  the  lower  parts  of  the  cavities. 

It  may  be  presumed  that  the  secretion  of  mucus  is  ef- 
fected here  by  vessels  which  are  mere  continuations  of  ar- 
teries spread  upon  a surface  analogous  to  the  exhalents, 
and  not  convoluted  in  circumscribed  masses,  as  in  the  case 
of  ordinary  glands. 

The  arteries  of  this  membrane  are  derived  from  various 
sources:  the  most  important  of  them  is  the  nasal  branch  of 
the  internal  maxillary,  which  passes  into  the  nose  through 
the  spheno-palatine  foramen,  and  is  therefore  called  the 
Spheno- Palatine  Aitery.  It  divides  into  several  twigs, 
which  are  spent  upon  the  different  parts  of  the  surface  of 
the  nasal  cavities.  Two  of  them  are  generally  found  on 
the  septum  of  the  nose:  one,  which  is  small,  passes  for- 
wards near  the  middle;  the  other,  which  is  much  larger, 
is  near  the  lower  part  of  it. 

Two  small  arteries  called  the  anterior  and posterior  eth- 
moidal, which  are  branches  of  the  ophthalmic, enter  the  nose 

' See  Winslow,  section  X.  No.  357 ■ 


Olfactory  Nerves.  ' 7 

by  foramina  of  the  cribriform  plate  of  the  ethmoidal  bone. 
These  arteries  pass  from  the  orbit  to  the  cavity  of  the  cra- 
nium, ancl  then  through  the  cribriform  plate  to  the  nose. 
In  addition  to  these,  there  are  some  small  arteries  derived 
from  the  infra  orbital,  the  alveolar  and  the  palatine  which 
extend  to  the  Schneiderian  membrane;  but  they  are  not  of 
much  importance. 

The  veins  of  the  nose  correspond  with  the  arteries. 
Those  which  accompany  the  ethmoidal  arteries  open  into 
the  ocular  vein  of  the  orbit,  which  terminates  in  the  ca- 
vernous sinuses  of  the  head.  The  other  veins  ultimately 
terminate  in  the  external  jugulars. 

The  Nerves  of  the  nose  form  an  important  part  of  the 
structure:  they  are  derived  from  several  sources;  but  the 
most  important  branches  are  those  of  the  olfactory. 

The  olfactory  nerves  form  oblong  bulbs,  which  lie  on 
each  side  of  the  crista  galli,  on  the  depressed  portions  of 
the  cribriform  plate  of  the  ethmoid  bone,  within  the  dura 
mater.  These  bulbs  are  of  a soft  consistence,  and  resem- 
ble the  cortical  part  of  the  brain  mixed  with  streaks  of 
medullary  matter.  They  send  off  numerous  filaments, 
which  pass  through  the  foramina  of  the  ethmoid  bone,  and 
receive  a coat  from  the  dura  mater  as  they  pass  through  it. 

These  filaments  are  so  arranged  that  they  form  two 
rows,  one  running  near  to  the  septum,  and  the  other  to  the 
surface  of  the  cellular  part  of  the  ethmoid  bone,  and  the  os 
turbinatum:  and  in  addition  to  these  are  some  intermediate 
filaments. 

When  the  Schneiderian  membrane  is  peeled  from  the 
bones  to  which  it  is  attached,  these  nervous  filaments  are 
seen  passing  from  the  foramina  of  the  ethmoid  bone  to 
the  attached  surfaces:  one  row  passing  upon  that  which 
covered  the  septum,  and  the  other  to  that  of  the  opposite 


8 Split:  no -palatine  and  other  Nerves  of  the  Nose . 

side;  while  the  intermediate  filaments  take  an  anterior  di- 
rection, but  unite  to  the  membrane  as  soon  as  they  come 
in  contact  with  it. 

All  of  these  can  be  traced  downwards  on  the  aforesaid 
surfaces  of  the  membrane  for  a considerable  distance,  when 
they  gradually  sink  into  the  substance  of  the  membrane, 
and  most  probably  terminate  on  the  internal  villous  sur- 
face; but  they  have  not  been  traced  to  their  ultimate  ter- 
mination. They  ramify  so  that  the  branches  form  very 
acute  angles  with  each  other.  On  the  septum  the  different 
branches  are  arranged  so  as  to  form  brushes,  which  lie  in 
contact  with  each  other.  On  the  opposite  sides,  the  differ- 
ent ramifications  unite  so  as  to  form  a plexus. 

Dr.  Soemmering  published  last  year  some  very  elegant 
engravings  of  the  nose,  representing  one  of  his  dissections, 
which  appears  to  have  been  uncommonly  minute  and  suc- 
cessful.* These  represent  the  ramifications  as  becoming 
more  expanded  and  delicate  in  the  progress  towards  their 
terminations,  and  as  observing  a tortuous  course,  with 
very  short  meandering  flexures. 

It  is  to  be  observed  that  the  ramifications  of  the  olfac- 
tory nerve,  thus  arranged,  do  not  extend  to  the  bottom  of 
the  cavity.  On  the  external  side,  they  are  not  traced  lower 
than  the  lower  edge  of  the  ethmoid,  or  of  the  superior 
spongy  bone:  and  on  the  septum,  they  do  not  extend  to  the 
bottom,  although  they  are  lower  than  on  the  opposite  side. 

On  the  parts  of  the  membrane  not  occupied  by  the 
branches  of  the  olfactory  nerve,  several  other  nerves  can 
be  traced.  The  nasal  twig  of  the  ophthalmic  branch  of  the 
fifth  pair,  after  passing  from  the  orbit  into  the  cavity  of 
the  cranium,  proceeds  to  the  nasal  cavity  on  each  side  by 
a foramen  of  the  cribriform  plate;  and  after  sending  off 

* They  are  intitled,  leones  organorum  humanorum  olfactifs 


9 


Extent  of  the  Schneiderian  Membrane. 

some  fibrillse,  descends  upon  the  anterior  part  of  the  sep- 
tum to  the  point  of  the  nose.  The  spheno-palatine  nerve, 
which  is  derived  from  the  second  branch  of  the  fifth  pair, 
and  enters  the  nose  by  the  spheno-palatine  foramen,  is 
spread  upon  the  lower  part  of  the  septum  and  of  the  oppo- 
site side  of  the  nose  also,  and  transmits  a branch  through 
a canal  in  the  foramen  incisivum  to  the  mouth.  Several 
small  branches  also  pass  to  the  nose  from  the  palatine  and 
other  nerves;  but  those  already  mentioned  are  the  most 
important.  7 

A question  has  been  proposed,  whether  the  olfactory 
nerve  is  exclusively  concerned  in  the  function  of  smelling, 
or  whether  the  other  nerves  above  mentioned  are  also  con- 
cerned in  it.  It  seems  probable  that  this  function  is  exclu- 
sively performed  by  the  olfactory  nerve,  and  that  the  other 
nerves  are  like  the  ophthalmic  branch  of  the  fifth  pair,  with 
respect  to  the  optic  nerve.  In  proof  of  this,  it  is  asserted 
that  the  sense  of  smelling  has  entirely  ceased  in  some  cases, 
where  the  sensibility  to  mechanical  irritation  of  every  kind 
has  remained  unchanged.  If  the  olfactory  nerve  alone  is 
concerned  in  the  function  of  smelling,  it  follows,  that  this 
function  must  be  confined  to  the  upper  parts  of  the  nasal 
cavities;  but  it  ought  to  be  remembered,  that  the  structure 
of  the  Schneiderian  membrane,  in  the  lower  parts  of  these 
cavities,  appears  exactly  like  that  which  is  above. 

The  surface  of  the  nasal  cavities  and  their  septum,  when 
covered  with  the  Schneiderian  membrane,  corresponds 
with  the  osseous  surface  formerly  described.  The  mem- 
brane covers  the  bones  and  cartilage  of  the  septum,  so  as 
to  make  one  uniform  regular  surface.  From  the  upper 
part  of  the  septum,  it  is  continued  to  the  under  side  of  the 
cribriform  plate  of  the  ethmoid,  and  lines  it;  the  filaments 
of  the  olfactory  nerve  passing  through  the  foramina  of  that 
bone  into  the  fibrous  surface  of  the  membrane.  It  is  con- 
Vol.  II.  B 


10  Distribution  of  the  Schneiderian  Membrane 

tinued  from  the  septum,  and  from  the  cribriform  plate,  to 
the  internal  surface  of  the  external  nose,  and  lines  it.  It  is 
also  continued  backwards  to  the  anterior  surface  of  the 
body  of  the  sphenoidal  bone;  and,  passing  through  the  fora- 
mina or  openings  of  the  sphenoidal  cells,  it  lines  these 
cavities  completely;  but  in  these,  as  well  as  the  other  cavi- 
ties, its  structure  appears  somewhat  changed:  it  becomes 
thinner  and  less  vascular. 

At  the  above  mentioned  foramina,  in  some  subjects,  it 
forms  a plait  or  fold,  which  diminishes  the  aperture  con- 
siderably. 

From  the  upper  surface  of  the  nasal  cavities,  the  mem- 
brane is  continued  downwards  over  the  surface  opposite 
to  the  septum.  On  the  upper  flat  surfaces  of  the  cellular 
portions  of  the  ethmoid,  it  forms  a smooth  uniform  sur- 
face. After  passing  over  the  first  turbinated  bone,  or  that 
called  after  Morgagni,  it  is  reflected  into  the  groove,  or 
upper  meatus,  immediately  within  and  under  it:  the  fold 
formed  by  the  membrane,  as  it  is  reflected  into  the  mea- 
tus, is  rather  larger  than  the  bone;  and  the  edge  of  the 
fold  therefore  extends  lower  down  than  the  edge  of  the 
bone,  and  partly  covers  the  meatus  like  a flap,  consisting 
only  of  the  doubled  membrane.  This  fold  generally  con- 
tinues backwards  as  far  as  the  spheno-maxillary  foramen, 
which  it  closes;  the  periosteum,  exterior  to  the  foramen, 
passing  through  it,  and  blending  itself  with  the  fibrous 
surface  of  the  Schneiderian  membrane  within.  Here  the 
spheno-palatine  nerves  and  arteries  join  the  membrane. 
Below  this  meatus,  it  extends  over  the  middle  (formerly 
called  the  upper)  turbinated  bone,  and  is  reflected  or  fold- 
ed inwards  on  the  under  side  of  this  bone,  and  continued 
into  the  middle  meatus  below  it.  In  the  middle  meatus, 
which  is  partly  covered  by  the  last  mentioned  turbinated 
bone,  there  are  two  foramina:  one  communicating  with  the 


11 


on  the  Internal  Surface  of  the  Nose. 

maxillary  sinus;  and  the  other  with  the  anterior  cells  of  the 
ethmoid  and  the  frontal  sinuses.  The  aperture  into  the 
maxillary  sinuses  is  much  less  in  the  recent  head,  in  which 
the  Schneiderian  membrane  lines  the  nose,  than  it  is  in  the 
bare  bones.  A portion  of  the  aperture  in  the  bones  is  clo- 
sed by  the  Schneiderian  membrane,  which  is  extended  over 
it:  the  remainder  of  the  aperture  is  unclosed;  and  through 
this  foramen,  the  membrane  is  reflected  so  as  to  line  the 
whole  cavity.  As  a portion  of  the  foramen  is  covered  by 
the  membrane,  and  this  portion  as  well  as  the  other  parts 
of  the  cavity  is  lined  bv  the  membrane,  it  is  obvious  that 
at  the  place  where  the  membrane  is  extended  over  the  fo- 
ramen in  the  bone,  it  must  be  doubled;  or,  in  other  words, 
a part  of  the  aperture  of  the  maxillary  sinus  is  closed  by  a 
fold  of  the  Schneiderian  membrane. 

This  aperture  varies  in  size  in  different  subjects,  and  is 
often  equal  in  diameter  to  a common  quill.  It  is  situated 
in  the  middle  meatus,  and  is  covered  by  the  middle  turbi- 
nated bone:  immediately-  above  it,  is  a prominence  of  the 
cellular  structure  of  the  ethmoid  bone,  which  has  a curved 
or  semicircular  figure.  Near  this  prominence,  in  the  same 
meatus,  a groove  terminates,  which  leads  from  the  anterior 
ethmoid  cells  and  the  frontal  sinuses. 

From  the  middle  meatus,  the  membrane  proceeds  over 
the  inferior  turbinated  bone,  and  is  reflected  round  and 
under  it  into  the  lower  meatus.  It  appears  rather  larger 
than  the  bone  which  it  covers;  and  therefore  the  lower 
edge  of  the  bone  does  not  extend  so  low  as  the  lower  edge 
of  the  membrane,  which  of  course  is  like  a fold  or  plait. 
The  membrane  then  continues  and  lines  the  lower  meatus: 
here  it  appears  less  full  than  it  is  in  the  turbinated  bone. 
In  this  meatus,  near  to  its  anterior  eud,  is  the  lower  orifice 
of  the  lachrymal  duct:  this  is  simply  lined  by  the  Schnei- 
derian membrane,  which  is  continued  into  it,  and  forms 
no  plaits  er  folds  that  affect  the  orifice. 


12  Eustachian  Tube. — Observations  respecting  the  Nose. 


Ori  fice  of  the  Eustachian  Tube. 

Immediately  behind  each  of  the  nasal  cavities,  on  the 
external  side,  is  the  orifice  of  the  Eustachian  Tube.  It  has 
an  oval  form,  and  is  large  enough  to  admit  a very  large 
quill.  Its  position  is  oblique;  the  upper  extremity  being 
anterior  to  the  other  parts  of  the  aperture,  and  on  a line 
with  the  middle  meatus,  while  the  center  is  behind  the 
inferior  turbinated  bone.  The  lower  part  of  the  oval  is 
deficient.  This  tube  is  formed  posteriorly  by  a cartilagi- 
nous plate.  It  is  lined  by  the  membrane  continued  from 
the  nose. 

The  cavities  of  the  nose  answer  a twofold  purpose  in  the 
animal  economy:  they  afford  a surface  for  the  expan- 
sion of  the  olfactory  nerves;  and  a passage  for  the  exter- 
nal air  to  the  windpipe,  in  respiration. 

The  function  of  smelling  appears  to  be  dependent,  to  a 
certain  degree,  upon  respiration.  It  has  been  asserted 
that  unless  the  air  passes  in  a stream  through  the  nose, 
as  in  respiration,  the  perception  of  odour  does  not  take 
place;  that  in  persons  who  breathe  through  wounds 
and  apertures  in  the  windpipe,  the  function  of  smelling 
is  not  performed.  It  is  rather  in  confirmation  of  this 
proposition,  that  most  persons,  when  they  wish  to  have 
an  accurate  perception  of  any  odour,  draw  in  air  rapidly 
through  the  nose. 

Although  the  ultimate  termination  of  the  olfactory  nerve 
cannot  be  demonstrated  like  those  of  the  optic  and  au- 
ditory nerves,  it  is  probable,  from  the  appearance  of  the 
fibres,  while  they  are  distinguishable,  that  they  are 
finally  arranged  with  great  delicacy.  It  is  certain  that 
the  impressions  from  whence  we  derive  the  perceptions 
of  many  odours  must  be  very  slight;  as  some  odorous 
bodies  will  impregnate  the  air  of  a large  chamber,  for  a 
great  length  of  time,  without  losing  any  sensible  weight. 

With  respect  to  delicacy  of  structure  and  sensibility,  it  is 
probable  that  the  nose  holds  a middle  rank  between  the 


L3 


Use  of  the  Sinuses  of  the  Nose. 

eye  or  ear,  and  the  tongue:  and  on  this  account  the 
mucus  is  necessary  as  a covering  and  defence  of  its 
surface. 

It  has  been  ascertained,  by  the  investigations  of  chemists, 
that  this  mucus  contains  the  same  ingredients  as  the 
tears  already  described,  viz:  animal  mucus  and  water: 
with  muriate  of  soda,  and  soda  uncombined;  phosphate 
of  lime,  and  phosphate  of  soda. 

The  animal  mucus,  which  is  a most  important  ingredient 
in  the  composition,  resembles  the  mucilage  formed  by 
some  of  the  vegetable  gums  in  several  particulars;  and 
differs  from  them  in  others. 

The  mucus  of  the  nose,  if  it  remain  there  long  after  it  is 
secreted,  becomes  much  more  viscid  in  consistence, 
and  changes  from  a whitish  colour  to  one  which  par- 
takes more  or  less  of  the  yellow.  It  is  probable  that  an 
incipient  putrefaction  may  occasion  these  changes  in  it 

The  use  of  the  frontal,  maxillary  and  other  sinuses,  com- 
municating with  the  nose,  has  been  the  subject  of  some 
inquiry.  As  there  can  be  no  stream  of  air  through  them, 
and  as  the  membrane  lining  them  is  neither  so  thick, 
villous  nor  flexible  as  that  lining  the  nose,  it  may  be  con- 
cluded, a priori,  that  they  are  not  concerned  in  the  func- 
tion of  smelling.  This  opinion  is  strengthened  by  the 
fact,  that  very  young  children,  in  whom  these  sinuses 
scarcely  exist,  enjoy  the  sense  of  smelling  in  perfec- 
tion. The  following  fact  is  also  in  support  of  it.  The 
celebrated  Dessault  attended  a patient,  in  whom  one  of 
the  frontal  sinuses  was  laid  open  by  the  destruction  of 
the  bone  which  covered  it  anteriorly.  This  patient  was 
able  to  breathe  a short  time  through  the  sinus  when 
the  mouth  and  nose  were  closed:  At  the  request  of 
Dessault  he  breathed  in  this  manner  when  a cup  of 
some  aromatic  liquor  was  held  near  the  opening  of  the 
sinus:  and  had  not  the  least  perception  of  odour.  This 
experiment  was  repeated  several  times. 

Many  physiologists  believe  that  these  sinuses  have  an 
effect  in  modulating  the  voice. 


14 


CHAPTER  II. 

OF  THE  MOUTH. 

1 HE  general  cavity  of  the  mouth  is  formed  anteriorly 
and  laterally  by  the  connexion  of  the  lips  and  cheeks  to  the 
upper  and  lower  jaws;  so  that  the  teeth  and  the  alveoli  of 
both  jaws  may  be  considered  as  within  the  cavity.  Above, 
it  is  bounded  principally  by  the  palatine  processes  of  the 
upper  maxillary  and  palate  bones,  and  the  soft  palate, 
which  continues  backward  from  them  in  the  same  direc- 
tion. Below,  the  cavity  is  completed  by  several  muscles, 
which  proceed  from  almost  the  whole  internal  circumfer- 
ence of  the  lower  jaw,  and,  by  their  connexions  with  each 
other,  with  the  tongue  and  the  os  hyoides,  form  a floor  or 
bottom  to  it.  The  tongue  is  particularly  connected  to  this 
surface,  and  may  be  considered  as  resting  upon  and  sup- 
ported by  it. 

To  acquire  an  idea  of  the  parietes  of  this  cavity,  after 
studying  the  upper  and  lower  maxillary  bones,  the  orbicu- 
laris oris  and  the  muscles  connected  with  it,  especially  the 
buccinator,  ought  to  be  examined;  and  also  the  digastricus, 
the  mylo-'nyoideus,  genio-hyoideus,  and  genio-hyoglossus. 
By  this  it  will  appear  that  the  lips  and  cheeks,  and  the  ba- 
sis or  floor  of  the  mouth,  are  formed  in  a great  measure  by 
muscles.  Upon  the  internal  surface  of  these  muscles,  a por- 
tion of  cellular  and  adipose  substance  is  arranged,  as  well 
as  glandular  bodies  of  different  sizes;  and  to  these  is  at- 
tached the  membrane  which  lines  the  inside  of  the  mouth. 

This  membrane  passes  from  the  skin  of  the  face  to  the 
lips,  and  the  inside  of  the  mouth;  and,  although  it  is  really 


15 


Internal  Surface  of  the  Mouth. 

a continuation  of  the  skin,  there  is  so  great  a change  of 
structure,  that  it  ought  to  be  considered  as  a different  mem- 
brane. At  the  orifice  of  the  lips  it  is  extremely  thin,  and  so 
vascular  that  it  produces  the  fine  florid  colour  which  ap- 
pears there  in  health.  It  is  covered  by  a cuticle,  called  by 
some  anatomists,  Epithelium , which  has  a proportionate 
degree  of  delicacy,  and  can  be  separated  like  the  cuticle  in 
other  parts.  When  this  cuticle  is  separated,  the  lips  and  the 
membrane  of  the  mouth,  appear  to  be  covered  with  very 
fine  villi,  which  are  particularly  apparent  in  some  prepara- 
tions of  the  lips  after  injection  and  maceration.* 

Under  this  membrane  are  many  small  glandular  bodies 
of  a roundish  form,  whose  excretory  ducts  pass  through  it 
to  the  inner  surface  of  the  mouth,  for  the  purpose  of  lubri- 
fying  it  with  their  secretion,  which  is  mingled  with  the 
saliva. 

The  membrane,  which  lines  the  inside  of  the  lips  and 
cheeks,  is  somewhat  different  from  that  which  forms  the 
surface  of  the  orifice  of  the  mouth:  it  is  not  so  florid;  the 
bloodvessels  in  its  texture  are  larger  and  not  so  numerous. 
This  change,  however,  takes  place  very  gradually,  in  the 
progress  of  the  membrane,  from  the  orifice  of  the  lips  to 
the  back  part  of  the  cheeks.  Glandular  bodies,  like  those 
of  the  lips,  are  situated  immediately  exterior  to  this  mem- 
brane of  the  cheeks,  between  it  and  the  muscles:  their 
ducts  open  on  its  surface.  These  glands  are  called  Buc- 
cales. 

This  lining  membrane  is  continued  from  the  internal 
surface  of  the  lips  and  cheeks  to  the  alveolar  portions  of 
the  upper  and  lower  jaws,  which  are  in  the  cavity  of  the 
mouth,  and  covers  them,  adhering  firmly  to  the  periosteum. 

* Ruysch  liad  a fine  preparation  of  this  structure.  See  Thesaurus  VII 
Tab  III.  Fig.  5. 


16  (jams — Surface  of  the  Hard  Palate . 

The  teeth  appear  to  have  passed  through  apertures  in  this 
membrane,  and  are  surrounded  by  it  closely  at  their  res- 
pective necks. 

The  portion  of  membrane,  which  thus  invests  the  jaws, 
constitutes  the  gums;  which  have  now  acquired  a texture 
very  different  from  that  of  the  membrane,  from  which  they 
were  continued.  They  are  extremely  firm  and  dense,  and 
very  vascular.  It  is  probable  that  their  ultimate  structure 
is  not  perfectly  undertsood. 

In  the  disease  called  scurvy , they  tumify  and  lose  the 
firmness  of  their  texture:  they  acquire  a livid  colour,  and 
are  much  disposed  to  hemorrhage. 

From  the  alveoli  of  the  upper  jaw,  the  lining  membrane 
is  continued  upon  the  palatine  processes  of  the  upper  max- 
illary and  palate  bones,  or  the  roof  of  the  mouth. 

This  membrane  of  the  palate  is  not  quite  so  firm  as  that 
of  the  gums,  and  is  also  less  florid:  it  adheres  firmly  to 
the  periosteum,  and  thus  is  closely  fixed  to  the  bones. 
There  is  generally  a ridge  on  its  surface,  immediately  un- 
der the  suture  between  the  two  upper  maxillary  bones;  and 
some  transverse  ridges  are  also  to  be  seen  upon  it.  On  the 
internal  surface  of  this  membrane  are  small  glandular  bo- 
dies, whose  ducts  open  on  the  surface  of  the  palate. 

It  is  asserted,  that  this  membrane  has  a limited  degree 
of  that  sensibility  which  is  essential  to  the  function  of  tast- 
ing; and,  that  if  certain  sapid  substances  are  carefully  appli- 
ed to  it,  their  respective  tastes  will  be  perceived,  although 
they  have  not  been  in  contact  with  the  tongue. 

The  membrane  is  continued  from  the  bones  above  men- 
tioned to  the  soft  palate,  or  velum  pendulum  palati,  which 
is  situated  immediately  behind  them.  This  soft  palate  may 
be  considered  as  a continuation  of  the  partition  between 
the  nose  and  mouth:  it  is  attached  to  the  posterior  edge  of 


17 


Soft  Palate — Uvula. 

the  palatine  processes  of  the  ossa  palati,  and  to  the  ptery- 
goid processes  of  the  sphenoidal  bone.  Its  interior  struc- 
ture is  muscular.  The  upper  surface  is  covered  by  the 
membrane  of  the  nose,  the  lower  surface  by  the  membrane 
which  lines  the  mouth. 

The  muscles,  which  contribute  to  the  composition  of 
this  structure,  are  the  circumflexus  and  the  levatores  palati 
above,  and  the  constrictores  isthmi  faucium  and  palato-pha- 
ryngei  below.  (See  Vol.  I.  page  187 — 188.)  Thus  com- 
posed, the  soft  palate  constitutes  the  back  part  of  the  par- 
tition between  the  nose  and  mouth.  When  viewed  from 
before,  with  the  mouth  open,  it  presents  towards  the  tongue 
an  arched  surface,  which  continues  downward  on  each  side 
until  it  comes  nearly  in  contact  with  the  edges  of  that 
organ.  On  each  of  the  lateral  parts  of  this  arch,  are  two 
pillars,  or  rather  prominent  ridges,  which  project  into  the 
mouth.  These  ridges  are  at  some  distance  from  each  other 
below,  and  approach  much  nearer  above,  so  that  they  in- 
clude a triangular  space.  They  are  called  the  lateral  half 
arches  of  the  palate.  Each  of  them  is  formed  by  a plait  or 
fold  of  the  skin,  and  contains  one  of  the  two  last  mention- 
ed muscles:  the  anterior,  the  constrictor  isthmi  faucium; 
the  posterior,  the  palato  pharyngeus.  These  muscles,  of 
course,  dra.w  the  palate  down  toward  the  tongue  when 
they  contract. 

From  the  center  of  the  arch,  near  its  posterior  edge,  is 
suspended  the  uvula,  a conical  body,  which  varies  in 
length  from  less  than  half  an  inch  to  rather  more  than  one 
inch.  It  is  connected  by  its  basis  to  the  palate;  but  its  apex 
is  loose  and  pendulous.  This  body  is  covered  by  the  lining 
membrane  of  the  mouth.  It  contains  many  small  glands, 
and  a muscle  also,  the  azygos  uvulae,  which  arises  from 
the  posterior  edge  of  the  ossa  palati,  at  the  suture  which 
Vol.  II.  C 


18 


Tongue. 

connects  them  to  each  other,  and,  passing  posteriorly  upon 
the  soft  palate,  extends  from  the  basis  to  the  apex  of  the 
uvula,  into  which  it  is  inserted.  By  the  action  of  this  mus- 
cle, the  length  of  the  uvula  can  be  very  much  dimisnihed: 
and  when  its  contraction  ceases,  that  body  is  elongated. 

The  pendulous  part  of  the  uvula  can  also  be  moved,  in 
certain  cases,  to  either  side. 

It  is  commonly  supposed,  that  the  principal  use  of  this 
little  organ  is  to  modulate  the  voice;  but  there  are  good 
reasons  for  believing,  that  it  has  another  object.  It  was 
remarked  by  Fallopius,  (and  the  observation  has  been  con- 
firmed by  many  surgeons  since  his  time)  that  the  uvula 
may  be  removed  completely  without  occasioning  any  alter- 
ation of  the  voice,  or  any  difficulty  in  deglutition,  if  the  soft 
palate  be  left  entire. 

The  soft  palate  is  so  flexible,  that  it  yields  to  the  actions 
of  the  levatores  palati,  which  draw  it  up  so  as  to  close  the 
posterior  nares  completely. 

It  also  yields  to  the  circumflexi  or  tensores,  which  stretch 
it  so  as  to  do  away  its  arched  appearance. 

It  is  therefore  very  properly  called  the  Palatum  Molle. 
It  is  also  frequently  called  the  Velum  Pendulum  Palati , 
from  the  position  which  it  assumes. 

The  Tongue , 

Which  is  a very  important  part  of  this  structure,  is  re- 
tained in  its  position  and  connected  with  the.parts  adjoin- 
ing it,  by  the  following  arrangements. 

The  os  hyoides,  which,  as  its  name  imports,  resembles 
the  Greek  letter  v,  or  half  an  oval,  is  situated  rather  below 
the  angles  of  the  lower  jaw,  in  the  middle  of  the  upper  part 
of  the  neck.  It  is  retained  in  its  position  by  the  sterno- 
hyoidei  muscles,  which  connect  it  to  the  upper  part  of  the 


19 


Connexions  of  the  Tongue . 

sternum;  by  the  coraco-hyoidei,  which  pass  to  it  obliquely 
from  the  scapula;  by  the  thyro-hyoidei,  which  pass  to  it  di- 
rectly upward  from  the  thyroid  cartilage:  all  of  which  con- 
nect it  to  parts  below.  To  these  should  be  added  the  stylo- 
hyoidei,  which  pass  to  it  obliquely  from  behind  and  rather 
from  above;  the  mylo-hyoidei,  which  come  rather  ante- 
riorly from  the  lateral  parts  of  the  lower  jaw;  and  the  ge- 
nio-hyoidei,  which  arise  from  a situation  directly  anterior 
and  superior,  the  chin.  When  these  muscles  are  at  rest, 
the  situation  of  the  os  hyoides  is,  as  above  described,  below 
the  angles  of  the  lower  jaw:  when  those,  in  one  particular 
direction,  act  while  the  others  are  passive,  the  bone  may 
be  moved  upwards  or  downwards,  backwards  or  forwards, 
or  to  either  side.  This  bone  may  be  considered  as  the  basis 
of  the  tongue;  for  the  posterior  extremity  of  that  organ  is 
attached  to  it;  and  of  course  the  movements  of  the  bone 
must  have  an  immediate  effect  upon  those  of  the  tongue. 

The  tongue  is  a flat  body  of  an  oval  figure,  but  subject 
to  considerable  changes  of  form. 

The  posterior  extremity,  connected  to  the  os  hyoides, 
is  commonly  called  its  basis;  the  anterior  extremity,  which, 
when  the  tongue  is  quiescent,  is  rather  more  acute,  is  called 
its  apex. 

The  lower  surface  of  the  tongue  is  connected  with  a 
number  of  muscles,  which  are  continued  into  its  substance. 
This  connexion  is  such,  that  the  edges  of  the  tongue  are 
perfectly  free  and  unconnected;  and  so  is  the  anterior  ex- 
tremity for  a considerable  distance  from  the  apex  towards 
the  base. 

The  substance  of  the  tongue  consists  principally  of  mus- 
cular fibres**  intermixed  with  a delicate  adipose  substance. 
It  is  connected  to  the  os  hyoides  by  the  hyoglossus  mus- 
cle and  also  by  some  other  muscular  fibres,  as  well  as  by 


20 


Structure  of  the  Tongue. 

a dense  membranous  substance,  which  appears  to  perform 
the  part  of  a ligament.  This  connexion  is  also  strengthened 
by  the  continuance  of  the  integuments  from  the  tongue  to 
the  epiglottis  cartilage,  to  be  hereafter  described;  for  that 
jcartilage  is  attached  by  ligaments  to  the  os  hyoides. 

The  tongue  is  thin  at  its  commencement  at  the  os  hy- 
oides; but  it  soon  increases  in  thickness.  The  muscular 
fibres  in  its  composition  have  been  considered  as  intrinsic, 
or  belonging  wholly  to  its  internal  structure;  and  extrinsic, 
or  existing  in  part  outside  of  this  structure.  The  linguales 
muscles  are  intrinsic:  (Vol.  I,  page  184.)  they  are  situa- 
ted near  the  under  surface  of  the  tongue,  one  on  each  side, 
separated  from  each  other  by  the  genio-glossi  muscles,  and 
extending  from  the  basis  of  the  tongue  to  its  apex.  These 
muscles  can  be  easily  traced  as  above  described;  but  there 
are  also  many  fibres  in  the  structure  of  the  tongue,  which 
seem  to  pass  in  every  direction,  and  of  course  are  different 
from  those  of  the  linguales  muscles.  To  these  two  sets  of 
fibres  are  owing  many  of  the  immensely  varied  motions  of 
the  different  parts  of  the  tongue. 

In  addition  to  these,  are  the  extrinsic  muscles,  which 
originate  from  the  neighbouring  parts,  and  are  inserted 
and  continued  into  the  substance  of  the  tongue. 

Among  the  most  important  of  these  muscles,  are  those 
which  proceed  from  the  chin,  or  the  genio-hyoglossi.  They 
are  in  contact  with  each  other;  their  fibres  radiate  from 
a central  point  on  the  inside  of  the  chin,  and  are  inserted 
into  the  middle  of  the  lower  surface  of  the  tongue:  the  in- 
sertion commencing  at  a short  distance  from  its  apex,  and 
continuing  to  its  base. 

As  the  genio-hyo-glossi  muscles  have  a considerable 
degree  of  thickness,  they  add  much  to  the  bulk  of  the 
tongue  in  the  middle  of  the  posterior  parts  of  it. 


21 


Upper  Surface  of  the  Tongue. 

The  hyo-glossi  and  the  stylo-glossi,  being  continued  into 
the  posterior  and  lateral  parts,  contribute  also  to  the  bulk 
of  these  parts. 

The  tongue,  thus  composed  and  connected,  lies,  when 
at  rest,  on  the  mylo-hyoidei  muscles;  and  the  space  between 
it  and  these  muscles  is  divided  into  two  lateral  parts  by 
the  above  described  genio-glossi:  In  the  space  above  men- 
tioned, is  a small  salivary  gland,  of  an  irregular  oval  form; 
the  greatest  diameter  of  which  extends  from  before  back- 
wards; and  its  edges  present  outwards  and  inwards.  It  has 
several  excretory  ducts,  the  orifices  of  which  form  a line 
on  each  side  of  the  tongue.  This  gland  is  very  prominent 
under  the  tongue;  and  when  the  tongue  is  raised  it  is  par- 
ticularly conspicuous:  it  is  called  the  Sublingual. 

The  lining  membrane  of  the  mouth  continues  from  the 
inside  of  the  alveoli  of  the  lower  jaw,  which  it  covers,  over 
the  sublingual  glands  to  the  lower  surface  of  the  tongue. 
In  this  situation  it  is  remarkably  thin;  but,  as  it  proceeds  to 
the  upper  surface  .of  the  tongue,  its  texture  changes  con- 
siderably; and  on  this  surface  it  constitutes  the  organ  of 
taste. 

The  upper  surface. of  the  tongue,  although  it  is  continued 
from  the  thin  membrane  above  described,  is  formed  by  a 
rough  integument  which  consists,  like  the  skin,  of  three 
laminae.  The  cuticle  is  very  thin;  and  under  it,  the  rete 
mucosum*  is  thicker  and  softer  than  in  other  places. 

The  true  skin  here  abounds  with  eminences  of  various 
sizes  and  forms,  all  of  which  are  denominated  Papillce. 
The  largest  of  these  are  situated  on  the  posterior  part  of 

* M.  Bichat  appears  to  jjave  had  doubts  whether  the  real  rete  muco- 
sum  existed  here.  He  says  that  he  could  only  perceive  a decussation  of 
vessels  in  the  intervals  of  the  papillae,  which,  as  he  supposes,  occasioned 
the  florid  colour  of  the  tongue. 


22 


Papilla:  of  the  Tongue. 

the  tongue,  and  are  so  arranged  that  they  form  an  angle 
rather  acute,  with  its  points  backwards.  They  are  com- 
monly nine  in  number:  they  resemble  an  inverted  cone; 
or,  are  larger  at  their  head  than  their  basis.  They  are  situ- 
ated in  pits  or  depressions,  to  the  bottoms  of  which  they 
are  connected.  In  many  of  them  there  are  follicles,  or  per- 
forations, which  have  occasioned  them  to  be  regarded  as 
glands.  They  are  called  Papillce  Maximce , or  Capitatce. 

The  papillae,  next  in  size,  are  denominated  fungiform 
by  some  anatomists,  and  Medics  or  Semilenticulares  by 
others.  They  are  nearly  cylindrical  in  form,  with  their 
upper  extremities  regularly  rounded.  They  are  scattered 
over  the  upper  surface  of  the  tongue,  in  almost  every  part 
of  it,  at  irregular  distances  from  each  other. 

The  third  class  are  called  conoidal  or  villous.  They  are 
very  numerous,  and  occupy  the  greatest  part  of  the  surface 
of  the  tongue.  Although  they  are  called  conoidal , there  is 
a great  difference  in  their  form;  many  of  them  being  irre- 
gularly angular  and  serrated,  as  well  as  conical. 

Soemmering  and  other  German  anatomists  consider 
the  smallest  papillae  as  a fourth  class,  which  they  call  the 
fliform:  these  lie  between  the  others. 

It  is  probable  that  these  papillae  are  essential  parts  of 
the  organ  of  taste;  and  their  structure  is  of  course  an  in- 
teresting object  of  inquiry. 

The  nerves  of  the  tongue  have  been  traced  to  the  papil- 
lae, and  have  been  compared  by  some  anatomists  to  the 
stalk  of  the  apple,  while  the  papillae  resembled  the  fruit; 
but  their  ultimate  termination  does  not  appear  to  have 
been  ascertained.* 

* In  the  explanation  of  the  plates,  referred  to  in  the  following  sen- 
tence, Soemmering  observes,  that  when  the  fibrills  of  the  lingual  nerve 
of  the  fifth  pair  are  traced  to  the  papilla  of*the  second  class,  they  swell 


Bloodvessels  of  the  Tongue. 


. 23 

Soemmering  has  lately  published  some  elegant  engraved 
copies  of  drawings  of  these  papillae,  when  they  were  mag- 
nified twenty-five  times;  from  which  it  appears  that  a very 
large  number  of  vessels,  particularly  of  arteries,  exist  in 
them.  These  vessels  are  arranged  in  a serpentine  direc- 
tion, and  are  prominent  on  the  surface;  but  they  appear 
doubled,  and  the  most  prominent  part  is  the  doubled  end. 
This  arrangement  of  vessels  is  perceptible  on  the  sides  of 
the  tongue,  as  well  as  on  the  papillae. 

Behind  the  large  papillae  is  a foramen,  first  described  by 
Morgagni,  and  called  by  him  Foramen  Caecum.  It  is  the 
orifice  of  a cavity  which  is  not  deep;  the  excretory  ducts 
of  several  mucous  glands  open  into  it. 

On  the  upper  surface  of  the  tongue,  a groove  is  often  to 
be  seen,  which  is  called  the  linea  mediana , and  divides  it 
into  two  equal  lateral  parts.  Below,  the  lining  membrane 
of  the  mouth,  as  it  is  continued  from  the  lower  jaw  to  the 
tongue,  forms  a plait,  which  acts  as  a ligament,  and  is 
called  the  frcenum  linguae.  It  is  attached  to  the  middle  of 
the  tongue,  at  some  distance  behind  the  apex. 

The  tongue  is  well  supplied  with  bloodvessels,  which 
are  derived  from  the  lingual  branch  of  the  external  carotid 
on  each  side.  This  artery  passes  from  the  external  carotid, 
upwards,  inwards,  and  forwards,  to  the  body  of  the  tongue. 
In  this  course  it  sends  off  several  small  arteries  to  the  con- 
tiguous parts,  and  one,  which  is  spent  about  the  epiglottis 
and  the  adjoining  parts,  called  the  Dorsalis  Linguae.  About 
the  anterior  edge  of  the  hyo-glossus  muscle,  it  divides  into 
two  large  branches:  one  of  which,  called  the  Sublingual , 
passes  under  the  tongue  between  the  genio-glossus  and  the 

oat  into  a conical  form;  and  these  nervous  cones  are  in  such  close  con- 
tact with  each  other,  that  the  point  of  the  finest  needle  could  not  be 
insinuated  into  the  papillx  without  touching  a nerve 


24. 


Nerves  of  the  Tongue. 

sublingual  gland,  and  extends  near  to  the  symphysis  of  the 
under  jaw;  sending  branches  to  the  sublingual  gland,  to 
the  muscles  under  the  tongue,  to  the  skin,  and  the  lower 
lip.  The  other  is  in  the  substance  of  the  tongue,  on  the 
under  side  near  the  surface,  and  extends  to  the  apex. 

The  veins  of  this  organ  are  not  so  regular  as  the  arte- 
ries: they  communicate  with  the  external  jugular;  and 
some  of  them  are  always  very  conspicuous  under  the 
tongue:  these  are  called  ranular . 

It  is  to  be  observed,  that  the  vessels  on  each  side  have 
but  little  connexion  with  each  other;  for  those  of  one  side 
may  be  injected  while  the  others  continue  empty. 

The  tongue  is  also  well  supplied  with  nerves,  and  de- 
rives them  from  three  different  sources  on  each  side,  viz: 
from  the  fifth,  the  eighth,  and  ninth  pairs  of  the  head. 

The  lingual  portion  of  the  third  branch  of  the  fifth  pair, 
passing  under  the  tongue,  enters  its  substance  about  the 
middle,  and  forms  many  minute  branches,  which  pass  to 
the  papillae  of  the  fore  part  of  the  tongue. 

The  glosso-pharyngeal  portion  of  the  eighth  pair,  send- 
ing off  several  branches  in  its  course,  passes  to  the  tongue 
near  its  basis,  and  divides  into  many  small  branches,  which 
are  spent  upon  the  sides  and  middle  of  the  root  of  the 
tongue,  and  also  upon  the  large  papillae. 

The  ninth  pair  of  nerves  are  principally  appropriated  to 
the  tongue.  They  pass  on  each  side  to  the  most  fleshy  part 
of  it,  and,  after  sending  one  branch  to  the  mylo-hyoideus, 
and  another  to  communicate  with  the  lingual  branch  of  the 
fifth  pair,  they  are  spent  principally  upon  the  genio-glossi, 
and  linguales  muscles. 

The  tongue  answers  a threefold  purpose.  It  is  the  prin- 
cipal organ  of  taste.  It  is  a very  important  agent  in  the 
articulation  of  words;  and  it  assists  in  those  operations 
updh  our  food,  which  are  performed  in  the  mouth. 


Parotid  Gland. 


25 


The  Salivary  Glands. 

The  salivary  glands  have  such  an  intimate  connexion 
with  the  mouth  that  they  may  be  described  with  it.* 

There  are  three  principal  glands  on  each  side:  the  Paro- 
tid, the  Submaxillary  and  the  Sublingual.  They  are  of  a 
whitish  or  pale  flesh-colour,  and  are  composed  of  many 
small  united  masses  or  lobuli,  each  of  which  sends  a small 
excretory  duct  to  join  similar  ducts  from  the  other  lobuli, 
and  thereby  form  the  great  duct  of  the  gland. 

The  Parotid  is  much  larger  than  the  other  glands.  It 
occupies  a large  portion  of  the  vacuity  between  the  mas- 
toid process  and  the  posterior  parts  of  the  lower  jaw.  It 
extends  from  the  ear  and  the  mastoid  process  over  a por- 
tion of  the  masseter  muscle,  and  from  the  zygoma  to  the 
basis  of  the  lower  jaw.  Its  name  is  supposed  to  be  derived 
from  two  Greek  words  which  signify  contiguity  to  the  ear. 
It  is  of  a firm  consistence.  It  receives  branches  from  the 
external  carotid  artery  and  from  its  facial  branch. 

From  the  anterior  edge  of  this  gland,  rather  above  the 
middle,  the  great  duct  proceeds  anteriorly  across  the  mas- 
seter muscle;  and,  after  it  has  passed  over  it,  bends  inward 
through  the  adipose  matter  of  the  cheek  to  the  buccinator 
muscle,  which  it  perforates  obliquely  and  opens  on  the 
inside  of  the  cheek  opposite  to  the  interval  between  the 
second  and  third  molar  teeth  of  the  upper  jaw.  The  aper- 
ture of  the  duct  is  rather  less  than  the  general  diameter  of 
it,  and  this  circumstance  has  the  effect  of  a valve.  When 
the  duct  leaves  the  parotid,  several  small  glandular  bodies 
are  often  attached  to  it,  and  their  ducts  communicate 


' For  a general  account  of  glands,  see  the  appendix  to  this  volume.. 

Vol.  II.  D 


26  Submaxillary  and  Sublingual  Glands. 

with  it.  The  main  duct  is  sometimes  called  after  Steno, 
who  first  described  it. 

When  the  mouth  is  opened  wide,  as  in  gaping,  there  is 
often  a jet  of  saliva  from  it  into  the  mouth. 

The  parotid  gland  furnishes  the  largest  proportion  of 
saliva. 

It  covers  the  nerve  called  Portia  Dura , after  it  has 
emerged  from  the  foramen  stylo-mastoideum. 

The  second  gland  is  called  the  Submaxillary.  It  is  much 
smaller  than  the  parotid,  and  rather  round  in  form.  It  is 
situated  immediately  within  the  angle  of  the  lower  jaw, 
between  it,  on  the  outside,  and  the  tendon  of  the  digastric 
muscle  and  the  ninth  pair  of  nerves  internally.  Its  poste- 
rior extremity  is  connected  by  cellular  membrane  to  the 
parotid  gland;  its  anterior  portion  lies  over  a part  of  the 
mylo-hyoideus  muscle;  and  from  it  proceeds  the  excretory 
duct,  which  is  of  considerable  length,  and  passes  between 
the  mylo-hyoideus  and  the  genio-glossus  muscles  along 
the  under  and  inner  edge  of  the  sublingual  gland.  In  this 
course  the  duct  is  sometimes  surrounded  with  small  glan- 
dular bodies,  which  seem  to  be  appendices  of  the  sublin- 
gual gland.  It  terminates  under  the  tongue,  on  the  side  of 
the  frsenum  linguae,  by  a small  orifice  which  sometimes 
forms  a papilla. 

The  orifice  is  often  smaller  than  the  duct;  in  conse- 
quence of  which,  obstruction  frequently  occurs  here,  and 
produces  the  disease  called  ranula. 

The  sublingual  gland,  which  has  already  been  mention- 
ed, lies  so  that,  when  the  tongue  is  turned  up,  it  can  be  seen 
protruding  into  the  cavity  of  the  mouth,  and  covered  by7 
the  lining  membrane,  which  seems  to  keep  it  fixed  in  its 
place.  It  lies  upon  the  mylo-hyoideus,  by  the  side  of  the 
genio-hyoideus;  and  is  rather  oval  in  form  and  flat.  Its 


27 


Saliva. — Motions  of  the  Tongue. 

greatest  length  is  from  before  backwards;  its  position  is 
rather  oblique,  one  edge  being  placed  obliquely  inwards 
and  upwards,  and  the  other  outwards  and  downwards.  It 
has  many  short  excretory  ducts,  which  open  by  orifices 
arranged  in  aline  on  each  side:  they  are  discovered  with 
difficulty,  on  account  of  their  small  size,  and  sometimes 
amount  to  eighteen  or  twenty  in  number.  In  some  few 
instances,  this  gland  sends  off  a single  duct,  which  com- 
municates with  the  duct  of  the  submaxillary  gland. 

The  salivary  fluid  secreted  by  these  glands  is  inodo- 
rous, insipid,  and  limpid,  like  water;  but  much  more  vis- 
cid, and  of  greater  specific  gravity.  Water  constitutes  at 
least  four  fifths  of  its  bulk;  and  animal  mucus  one  half  of 
its  solid  contents.  It  also  contains  some  albumen,  and 
several  saline  substances:  as  the  muriate  of  soda,  and  the 
phosphates  of  lime,  of  soda,  and  of  ammonia. 

It  is  probable  that  this  fluid  possesses  a solvent  power 
with  respect  to  the  articles  of  food. 

There  are  small  glandular  bodies,  situated  between  the 
masseter  and  buccinator  muscles,  opposite  to  the  last  mo- 
lar tooth  of  the  upper  jaw,  whose  nature  is  not  well  under- 
stood: they  are  called  Glandulcc  Molares. 

The  motions  of  the  tongue  are  very  intelligible  to  a per- 
son who  has  a preparation  of  the  lower  jaw  before  him, 
with  the  tongue  in  its  natural  situation,  and  the  mus- 
cles, which  influence  it,  properly  dissected.  Its  com- 
plicated movements  will  appear  the  necessary  result  of 
the  action  of  those  muscles  upon  it,  and  the  os  hyoides; 
and  also  upon  the  larynx,  with  which  the  os  hyoides  is 
connected.  The  muscular  fibres  of  the  tongue  itself  are 
also  to  be  taken  into  this  view,  as  they  act  a very  im- 
portant part. 

Although  the  tongue  appears  very  necessary,  in  a me- 


28 


Observations  on  the  Tongue. 

chanical  point  of  view,  to  the  articulation  of  many 
words,  yet  there  are  cases  where  it  has  been  entirely 
deficient,  in  which  the  parties,  thus  affected,  have  been 
able  to  speak  very  well  in  general,  as  well  as  to  distin- 
guish different  tastes.* 

The  tongue  is  also  a very  delicate  organ  of  touch.  Wc 
can  perceive  the  form  of  the  teeth,  and  the  state  of  the 
surface  of  the  mouth,  more  accurately  by  the  applica- 
tion of  the  tongue  than  of  the  fingers. 

Of  the  three  nerves  which  go  to  the  tongue,  it  is  gene- 
rally supposed  that  the  lingual  portion  of  the  third 
branch  of  the  fifth  pair  is  most  immediately  concerned 
in  the  function  of  tasting,  as  it  passes  to  the  front  part 
of  the  surface  of  the  tongue.  The  glosso-pharyngeal 
are  probably  concerned  in  the  same  function  on  the 
posterior  part,  while  the  ninth  pair  of  nerves  seems  prin- 
cipally spent  upon  the  muscular  parts  of  the  organ. 

It  is  obvious  that  the  tongue  is  most  copiously  supplied 
with  nerves.  This  probably  accounts  for  the  great  faci- 
lity of  its  motions,  and  the  power  of  continuing  them. 

* There  is  a very  interesting  paper  on  this  subject,  in  the  Memoirs 
of  the  Academy  of  Sciences  for  the  year  1718,  by  Jussieu,-  in  which 
he  describes  the  case  of  a female,  fifteen  years  old,  examined  by  him- 
self, who  was  born  without  a tongue.  In  this  paper  he  refers  to  ano- 
ther case,  described  by  Holland,  a surgeon  of  Saumur,  of  a boy  nine 
years  old,  whose  tongue  was  destroyed  by  gangrene.  In  each  of  these 
cases  the  subject  was  able  to  articulate  very  well,  with  the  exception 
of  a few  letters:  and  also  enjoyed  the  sense  of  taste. 


29 


CHAPTER  III. 

OF  THE  THROAT. 

To  avoid  circumlocution,  the  word  throat  is  used  as  a 
general  term  to  comprehend  the  structure  which  occurs 
behind  the  nose  and  mouth,  and  above  the  oesophagus  and 
trachea.  This  structure  consists, 

1st,  Of  the  parts  immediately  behind  the  mouth,  which 
constitute  the  Isthmus  of  the  Fauces: 

2d,  Of  the  parts,  which  form  the  orifice  of  the  windpipe, 
or  the  Larynx ; — and 

3d,  Of  the  muscular  bag,  which  forms  the  cavity  behind 
the  nose  and  mouth  that  terminates  in  the  oesophagus,  or 
the  Pharynx. 


SECTION  I. 

Of  the  Isthmus  of  the  Fauces. 

IN  the  back  part  of  the  mouth,  on  each  side,  are  to  be 
seen  the  two  ridges  or  half  arches,  passing  from  the  soft 
palate  to  the  root  of  the  tongue,  mentioned  in  page  17,  and 
said  to  be  formed  by  plaits  of  the  skin  containing  muscu- 
lar fibres.  The  anterior  plait,  which  contains  the  muscle 
called  Constrictor  Isthmi  Faucium , passes  directly  from 
the  side  of  the  root  of  the  tongue  to  the  palate,  and  termi- 
nates near  the  commencement  of  the  uvula.  The  posterior 
plait  runs  from  the  palate  obliquely  downwards  and  back- 
wards, as  it  contains  the  palato-pharyngeus  muscle,  which 
passes  from  the  palate  to  the  upper  and^josterior  part  of 
the  thyroid  cartilage. 


30 


T onsils.— ^Epiglottis. 

In  the  triangular  space  between  these  ridges  is  situated 
a glandular  body,  called  the  Tonsil  or  Amygdala.  This 
gland  has  an  oval  form,  its  longest  diameter  extending 
from  above  downwards.  Its  surface  is  rather  convex,  its 
natural  colour  is  a pale  red.  On  its  surface  are  the  large 
orifices  of  many  cells  of  considerable  size,  which  exist 
throughout  the  gland.  These  cells  often  communicate 
with  each  other,  so  that  a probe  can  be  passed  in  at  one 
orifice  and  out  at  the  other. 

Into  these  cells  open  many  mucus  ducts,  which  dis- 
charge the  mucus  of  the  throat,  for  the  purpose  of  lubrica- 
ting the  surface,  and  facilitating  the  transmission  of  solid 
food. 

The  epiglottis,  or  fifth  cartilage  of  the  larynx,  is  situated 
at  the  root  of  the  tongue,  in  the  middle,  between  the  ton- 
sils. The  part  which  is  in  sight  is  partly  oval  in  form,  and 
of  a whitish  colour.  Its  position,  as  respects  the  tongue,  is 
nearly  perpendicular,  and  its  anterior  surface  rather  convex. 

The  membrane  continued  from  the  tongue  over  the  epi- 
glottis is  so  arranged  that  it  forms  a plait,  which  extends 
from  the  middle  of  the  root  of  the  tongue  along  the  middle 
of  the  anterior  surface  of  the  epiglottis,  from  its  base  up- 
wards. 

On  each  side  of  this  plait,  or  frsenum,  at  the  junction  of 
the  surfaces  of  the  tongue  and  of  the  epiglottis,  there  is 
often  a depression,  in  which  small  portions  of  food  some- 
times remain;  and  a small  frsenum,  similar  to  that  above 
described,  is  sometimes  seen  on  the  outside  of  each  of 
these  cavities. 

The  epiglottis  is  situated  immediately  before  the  open- 
ing into  the  larynx. 

The  above  described  parts  can  be  well  ascertained  in  the 
living  subject,  by  a person  who  has  a general  knowledge 


Cricoid,  and  Thyroid  Cartilages.  31 

of  the  structure.  Thus,  looking  into  the  mouth,  with  the 
tongue  depressed,  the  uvula  and  soft  palate  are  in  full  view 
above,  and  the  epiglottis  is  very  perceptible  below;  while 
the  two  ridges  or  lateral  half-arches  can  be  seen  on  each 
side,  with  the  tonsil  between  them. 

SECTION  II. 

Of  the  Larynx. 

IN  this  structure  are  five  cartilages,  upon  which  its 
form  and  strength  depends,  viz:  the  Cricoid , the  Thyroid , 
the  two  Arytenoid , and  the  Epiglottis.  These  cartilages 
are  articulated  to  each  other,  and  are  supplied  with  mus- 
cles by  which  certain  limited  motions  are  effected. 

The  basis  of  the  structure  is  a cartilaginous  ring,  called 
the  Cricoid  cartilage,  which  may  be  considered  as  the  com- 
mencement of  the  windpipe. 

It  may  be  described  as  an  irregular  section  of  a tube: 
its  lower  edge,  connected  with  the  windpipe,  being  nearly 
horizontal  when  the  body  is  erect;  and  the  upper  edge 
very  oblique,  sloping  from  before,  backwards  and  upwards: 
in  consequence  of  this,  it  has  but  little  depth  before,  but 
is  eight  or  nine  lines  deep  behind. 

The  Thyroid  cartilage  is  a single  plate,  bent  in  such  man- 
ner that  it  forms  an  acute  angle  with  two  similar  broad 
surfaces  on  each  side  of  it.  It  is  so  applied  to  the  cricoid 
cartilage,  that  the  lower  edge  of  the  angular  part  is  at  a 
small  distance  above  the  front  part  of  that  cartilage,  and 
connected  to  it  by  ligamentous  membrane:  while  its  broad 
sides  are  applied  to  it  laterally,  and  thus  partially  inclose  it. 

The  upper  edge  of  the  angular  part  of  the  thyroid  car- 
tilage forms  a notch;  and  the  natural  position  of  the  carti- 
lage is  such,  that  this  part  is  very  prominent  in  the  neck:  it 
is  called  the  Pomum  Adami. 


32  Arytenoid  Cartilages  and  Ligaments. 

Both  the  upper  and  lower  edges  of  the  thyroid  cartilage 
terminate  posteriorly  in  processes,  which  are  called  Cor- 
nua. The  two  uppermost  are  longest:  they  are  joined  by 
ligaments  to  the  extremities  of  the  os  hyoides.  The  lower 
and  shorter  processes  are  fixed  to  the  cricoid  cartilage. 
The  thyroid  cartilage,  therefore,  partly  rests  upon  the 
cricoid  cartilage  below,  and  is  attached  to  the  os  hyoides 
above.  It  is  influenced  by  the  muscles  which  act  upon  the 
os  hyoides,  and  also  by  some  muscles  which  are  inserted 
into  itself.  It  is  moved  obliquely  downwards  and  forwards, 
in  a slight  degree,  upon  the  cricoid  cartilage  by  a small 
muscle,  the  crico-thyroideus,  which  arises  from  that  car- 
tilage and  is  inserted  into  it. 

The  Arytenoid  cartilages  are  two  small  bodies  of  a tri- 
angular pyramidal  form,  but  slightly  curved  backwards. 
They  are  placed  upon  the  upper  and  posterior  edge  of  the 
cricoid  cartilage,  near  to  each  other;  and  their  upper  ends, 
taken  together,  resemble  the  mouth  of  a pitcher  or  ewer; 
from  which  circumstance  their  name  is  derived.  Their 
bases  are  broad;  and  on  their  lower  surfaces  is  a cavity, 
which  corresponds  with  the  convex  edge  of  the  cricoid 
cartilage,  to  which  they  are  applied.  At  these  places,  a 
regular  movable  articulation  is  formed,  by  a capsular 
ligament  between  each  of  these  cartilages  and  the  thyroid; 
in  consequence  of  which  they  can  be  inclined  backward  or 
forward,  inward  or  outward. 

From  the  anterior  part  of  each  of  these  cartilages,  near 
the  base,  a tendinous  cord  passes  forward,  in  a direction 
which  is  horizontal  when  the  body  is  erect,  to  the  internal 
surface  of  the  angle  of  the  thyroid.  These  ligaments  are 
not  perfectly  parallel  to  each  other;  for  they  are  nearer  be- 
fore than  behind.  The  aperture  between  them  is  from  two 
to  five  lines  wide  when  the  muscles  are  not  in  action;  and 


33 


Epiglottis. 

this  aperture  is  the  orifice  of  the  windpipe:  for  the  exte- 
rior space,  between  these  ligaments  and  the  circumference 
of  the  cricoid,  is  closed  up  by  membrane  and  muscle.  At 
a small  distance  above  these  ligaments  are  two  others, 
which  also  pass  from  the  arytenoid  to  the  thyroid  carti- 
lages. They  are  not  so  tendinous  and  distinct  as  the  first 
mentioned,  and  cannot  be  drawn  so  tense  by  the  muscles 
of  the  arytenoid  cartilages.  They  are  also  situated  at  a 
greater  distance  from  each  other,  and  thus  form  a large 
aperture. 

On  the  external  side  of  the  upper  extremity  of  each  of 
the  arytenoid  cartilages,  and  nearly  in  contact  with  it,  is  a 
small  cartilaginous  body,  not  so  large  as  a grain  of  wheat, 
and  nearly  oval  in  form.  These  are  connected  firmly  to 
the  arytenoid  cartilages,  and  are  called  their  appendices. 
Being  in  the  margin  of  the  aperture  of  the  larynx,  they 
have  an  effect  upon  its  form. 

The  arytenoid  cartilages  are  the  posterior  parts  of  the 
larynx:  the  Epiglottis , which  has  already  been  mentioned, 
is  the  anterior.  When  this  cartilage  is  divested  of  its  mem- 
brane, it  is  oval  in  its  upper  extremity,  and  rather  angular 
below,  terminating  in  a long  narrow  process  which  is  like 
the  stalk  of  a leaf.  It  is  firmly  attached  to  the  internal  surface 
of  the  angular  part  of  the  thyroid  by  this  lower  process; 
and,  being  placed  in  a perpendicular  position,  one  of  its 
broad  surfaces  is  anterior  towards  the  tongue,  and  the 
other  posterior,  towards  the  opening  of  the  windpipe. 

It  is  attached  to  the  os  hyoides  by  dense  cellular  texture 
or  ligament,  and  to  the  tongue  by  those  plaits  of  the  mem- 
brane of  the  mouth,  which  have  been  already  described. 

It  is  elastic,  but  more  flexible  than  the  other  cartilages; 
being  somewhat  different  in  its  structure.  Its  surface  is 
perforated  by  the  orifices  of  many  mucus  ducts. 

Vol.  II.  E 


34 


Ventricles  of  Morgagni. 

There  is  a small  space  between  the  lower  part  of  this 
cartilage  which  is  posterior,  and  the  upper  part  of  the  thy- 
roid and  the  ligament  passing  from  it  to  the  os  hyoides, 
which  are  anterior.  In  this  is  a substance,  which  appears 
to  consist  of  glandular  and  of  adipose  matter.  It  is  suppo- 
sed that  some  of  the  orifices  on  the  lower  part  of  the  epi- 
glottis communicate  with  this  substance. 

In  the  erect  position  of  the  body,  the  epiglottis  is  situa- 
ted rather  higher  up  than  the  arytenoid  cartilages,  and  at 
the  distance  of  ten  or  twelve  lines  from  them. 

The  membrane,  which  covers  the  epiglottis,  is  extended 
from  each  side  of  it  to  the  arytenoid  cartilages;  and  being 
continued  into  the  cavity  of  the  larynx,  as  well  as  upon  the 
general  surface  of  the  throat,  it  is  necessarily  doubled: 
this  doubling  forms  the  lateral  margins  of  the  orifice  of  the 
cavity  of  the  larynx.  In  these  folds  of  the  membrane  are 
seen  very  delicate  muscular  fibres,  called  the  Aryteno-epi- 
glottidei. 

The  membrane  continues  down  the  cavity  of  the  larynx, 
and,  covering  the  upper  ligaments,  penetrates  into  the  va- 
cuity between  them  and  the  lower  ligaments,  so  as  to  form 
a cavity  on  each  side  of  the  larynx,  opening  between  the 
two  ligaments,  which  is  called  the  Ventricle  of  Morgagni. 
The  shape  of  these  cavities  is  oblong.  Its  greatest  length 
extends  from  behind  forward,  on  each  side  of  the  opening 
into  the  windpipe  formed  by  the  two  lower  or  principal 
ligaments;  so  that  when  the  larynx  is  removed  from  the 
subject,  upon  looking  into  it  from  above,  you  perceive 
three  apertures:  one  in  the  middle,  formed  by  the  two 
lower  ligaments;  and  one  on  each  side  of  it,  between  the 
lower  and  upper  ligament,  which  is  the  orifice  of  the  ven- 
tricle of  Morgagni. 


Rima  Glottidis.— ^Glottis. 


35 


The  aperture  between  the  two  lower  ligaments  is  called 
the  Rima  Glottidis , or  Chink  of  the  Glottis ; the  upper  aper- 
ture, formed  by  the  fold  of  the  membrane  extending  from 
the  epiglottis  to  the  arytenoid  cartilages,  may  be  termed 
Glottis. 

If  the  windpipe  is  divided  near  the  larynx,  and  the  la- 
rynx inverted,  so  that  the  rima  glottidis  may  be  examined 
from  below,  the  structure  appears  still  more  simple:  it 
resembles  a septum  fixed  abruptly  in  the  windpipe,  with 
an  aperture  in  it  of  the  figure  of  the  rima  glottidis. 

The  anterior  surface  of  the  two  arytenoid  cartilages  is 
concave.  This  concavity  is  occupied  in  each  by  a glandu- 
lar substance,  which  lies  between  the  cartilage  and  the 
lining  membrane;  and  extends  itself  horizontally,  covered 
by  the  upper  ligament  of  the  glottis.  The  nature  of  these 
bodies  is  not  perfectly  understood;  but  they  are  supposed 
to  secrete  mucus. 

The  membrane,  which  lines  the  cavity  of  the  glottis, 
being  continued  from  the  mouth  and  throat,  resembles  the 
membranes  which  invest  those  parts.  In  some  places, 
where  it  is  in  close  contact  with  the  cartilages,  it  appears 
united  with  the  perichondrium,  and  acquires  more  firmness 
and  density. 

The  general  motions  of  the  larynx  are  very  intelligible 
to  those  who  are  acquainted  with  the  muscles  which  are 
connected  with  the  thyroid  cartilage,  and  which  move  the 
os  hyoides.  They  take  place  particularly  in  deglutition, 
and  in  some  modifications  of  the  voice;  and  also  in  vomit- 
ing. 

The  motions  of  the  particular  cartilages  on  each  other 
can  also  be  well  understood,  by  attending  to  the  origin  and 
insertion  of  the  various  small  muscles  connected  with 
them.  The  most  important  of  these  muscles  are  the  crico- 


36  Arteries  and  Nerves  of  Larynx. -General  Observations. 

arytenoidei  postici  and  laterales,  the  thyreo-arytenoidei, 
the  arytenoidei  obliqui,  and  the  arytenoideus  transversus. 
The  effects  of  their  actions  appear  to  be  the  dilating  or 
contracting  the  rima  glottidis,  and  relaxing  or  extending 
the  ligaments  which  form  it. 

The  arteries  of  the  larynx  are  derived  from  two  sources, 
viz:  the  superior  thyroid,  or  laryngeal  branch  of  the  ex- 
ternal carotid;  and  the  thyroid  branch  of  the  subclavian. 

The  nerves  of  the  larynx  also  come  to  it  in  two  very  dif- 
ferent directions  on  each  side.  It  receives  two  branches 
from  the  par  vagum:  one  which  leaves  that  nerve  high  up 
in  the  neck,  and  is  called  the  Superior  Laryngeal  branch; 
and  another  which  proceeds  from  it  after  it  has  passed 
into  the  cavity  of  the  thorax,  and  is  called  from  its  direc- 
tion the  Recurrent. 

The  extreme  irritability  of  the  glottis  is  unequivocally 
demonstrated  by  the  cough  which  is  excited  when  a 
drop  of  water,  or  any  other  mild  liquid,  or  a crumb  of 
bread  enters  it.  Notwithstanding  this,  a flexible  tube, 
or  catheter,  has  several  times  been  passed  into  the 
windpipe  through  the  rima  glottidis,  and  been  endured 
by  the  patient  a considerable  time. 

The  cough,  which  occurs  when  these  parts  are  irritated, 
does  not  appear  to  arise  exclusively  from  the  irritation 
of  the  membrane  within  the  glottis;  for,  if  it  were 
so,  mucilaginous  substances,  when  swallowed  slowly, 
could  not  suspend  it.  Their  effect  in  relieving  cough 
is  universally  known;  and  as  they  are  only  applied  to 
the  surface  exterior  to  the  glottis,  it  is  evident  that  the 
irritation  of  this  surface  must  also  produce  coughing. 

Several  curious  experiments  have  been  made  to  deter- 
mine the  effect  of  dividing  the  different  nerves  which 


Thyroid.  Gland.  37 

go  to  the  larynx;  by  which  it  appears  that  the  recurrent 
branches  supply  parts  which  are  essentially  necessary 
to  the  formation  of  the  voice,  whilst  the  laryngeal 
branches  supply  parts  which  merely  influence  its  mo- 
dulation, or  tone.  See  Mr.  Haighton’s  Essay  on  this 
subject: — Memoirs  of  the  Medical  Society  of  London, 
Vol.  III. 

The  Thyroid  Gland 

May  be  described  here,  although  a part  of  it  is  situated 
below  the  larynx. 

This  body  consists  of  two  lobes,  which  are  united  at 
their  lower  extremities  by  a portion  which  extends  across 
the  anterior  part  of  the  windpipe.  Each  lobe  generally 
rises  upwards  and  backwards  from  the  second  cartilagi- 
nous ring  of  the  windpipe  over  the  cricoid  cartilage  and  a 
portion  of  the  thyroid.  It  lies  behind  the  sterno-hyoidei 
and  sterno-thyroidei  muscles.  It  is  of  a reddish  brown 
colour,  and  appears  to  consist  of  a granulous  substance; 
but  its  ultimate  structure  is  not  understood.  It  is  plenti- 
fully supplied  with  blood,  and  receives  two  arteries  on 
each  side:  one  from  the  laryngeal  branch  of  the  external 
carotid;  and  the  other  from  the  thyroid  branch  of  the  sub- 
clavian. 

Notwithstanding  this  large  supply  of  blood,  there  is  no 
proof  that  it  performs  any  secretion;  for  although  several 
respectable  anatomists  have  supposed  that  they  discovered 
excretory  ducts  passing  to  the  windpipe,  larynx,  or  tongue, 
it  is  now  generally  agreed  that  such  excretory  ducts  are 
not  to  be  found.  Several  instances  have  however  occurred, 
in  which  air  has  been  forced,  by  violent  straining,  from 
the  windpipe  into  the  substance  of  this  gland. 


38 


SECTION  HI. 

Of  the  Pharynx. 

THE  pharynx  is  a large  muscular  bag,  which  forms  the 
great  cavity  behind  the  nose  and  mouth  that  terminates  in 
the  oesophagus. 

It  has  been  compared  to  a funnel,  of  which  the  oesopha- 
gus is  the  pipe;  but  it  differs  from  a funnel  in  this  respect, 
that  it  is  incomplete  in  front,  at  the  part  occupied  by  the 
nose  and  mouth  and  larynx. 

It  is  connected  above,  to  the  cuneiform  process  of  the 
occipital  bone,  to  the  pterygoid  processes  of  the  sphenoidal, 
and  to  both  the  upper  and  lower  maxillary  bones.  It  is  in 
contact  with  the  cervical  vertebra;  behind;  and,  opposite  to 
the  cricoid  cartilage,  it  terminates  in  the  oesophagus. 

If  the  pharynx  and  oesophagus  be  carefully  dissected  and 
detached  from  the  vertebrae,  preserving  the  connexion  of 
the  pharynx  with  the  head;  and  the  head  then  be  separated 
from  the  body,  by  dividing  the  articulation  of  the  atlas  and 
the  os  occipitis,  and  cutting  through  the  soft  parts  below 
the  larynx;  the  resemblance  to  a funnel  will  be  very  ob- 
vious. 

In  this  situation,  if  an  incision  be  made  from  above 
downwards  through  the  whole  extent  of  the  posterior  part 
of  the  pharynx,  the  communication  of  the  nose,  mouth,  and 
windpipe,  with  this  cavity,  will  be  seen  from  behind  at 
one  view. 

The  openings  into  the  nose,  or  the  posterior  nares,  ap- 
pear uppermost.  Their  figure  is  irregularly  oval  or  oblong: 
they  are  separated  from  each  other  by  a thin  partition,  the 
vomer.  Immediately  behind,  on  the  external  side  of  each 
of  these  orifices,  is  the  Eustachian  tube . 


39 


Structure  of  the  Pharynx. 

The  soft  palate  will  appear  extending  from  the  lower 
boundary  of  the  posterior  nares,  obliquely  backward  and 
downwards,  so  as  nearly  to  close  the  passage  into  the 
mouth.  The  uvula  hangs  from  it;  and,  on  each  side  of  the 
uvula,  the  edge  of  the  palate  is  regularly  concave. 

Below  the  palate,  in  the  isthmus  of  the  fauces,  are  the 
ridges  or  half-arches,  and  the  tonsils  between  them.  The 
half-arch  which  presents  first,  in  this  view,  runs  obliquely 
downward  and  backward,  and  not  parallel  to  the  other. 

Close  to  the  root  of  the  tongue  is  the  epiglottis  erect; 
and,  immediately  adjoining  it,  is  an  aperture  large  enough 
to  admit  the  end  of  a middle-sized  finger.  This  aperture 
is  widest  at  the  extremity  next  to  the  epiglottis,  and  rather 
narrower  at  the  other  extremity:  it  is  the  glottis  or  open- 
ing of  the  windpipe.  When  the  larynx  is  elevated,  the 
epiglottis  can  be  readily  depressed  so  as  to  cover  it  com- 
pletely. 

The  extremities  of  the  arytenoid  cartilages,  and  their 
appendices,  may  be  recognised  at  the  posterior  edge  of  the 
glottis.  At  a short  distance  below  this  edge,  the  asopha- 
gus  begins. 

The  Pharynx  is  composed  of  the  membrane  continued 
from  the  nose  and  mouth  internally,  and  of  a stratum 
of  muscular  fibres  externally.  The  internal  membrane 
is  very  soft  and  flexible,  and  perforated  by  many  mucife- 
roui  ducts.  The  surface  which  it  forms  is  rather  rough, 
owing  to  the  mucous  glands  which  it  covers.  It  has  a red 
colour,  but  not  so  deep  as  that  of  some  other  parts.  It  is 
connected  to  the  muscular  stratum  by  a loose  cellular 
membrane. 

The  muscular  coat  consists  of  three  different  portions, 
which  are  considered  as  so  many  distinct  muscles. 


40 


Structure  of  the  Pharynx. 

The  fibres  of  each  of  these  muscles  originate  on  each 
side,  and  run  in  an  oblique  direction  to  meet  in  the  mid- 
dle, thus  forming  the  posterior  external  surface  of  the 
dissected  pharynx. 

The  fibres  of  the  upper  muscle  originate  from  the  cu- 
neiform process  of  the  occipital  bone,  from  the  pterygoid 
processes  of  the  os  sphenoides,  and  from  the  upper  and 
lower  jaws,  near  the  last  dentes  molares,  on  each  side. 
They  unite  in  a middle  line  in  the  back  of  the  pharynx. 

The  fibres  of  the  middle  muscle  originate  principally 
from  the  lateral  parts  of  the  os  hyoides,  and  from  the  liga- 
ments which  connect  that  bone  to  the  thyroid  cartilage. 
The  superior  fibres  run  obliquely  upwards,  so  as  to  cover 
a part  of  the  first  mentioned  muscle,  and  terminate  in  the 
cuneiform  process  of  the  occipital  bone;  while  the  other 
fibres  unite  with  those  of  the  opposite  side  in  the  middle 
line. 

The  fibres  of  the  lower  muscle  arise  from  the  thyroid 
and  the  cricoid  cartilages,  and  terminate  also  in  the  mid- 
dle line.  Those  which  are  superior,  running  obliquely  up- 
wards; the  inferior,  nearly  in  a transverse  direction. 

It  is  obvious,  from  the  origin  and  insertion  of  these 
fibres,  that  the  pharynx  must  have  the  power  of  contract- 
ing its  dimensions  in  every  respect;  and,  particularly,  that 
its  diameter  may  be  lessened  at  any  place;  and  that  the 
whole  ma^  be  drawn  upwards. 


SYSTEM  OF  ANATOMY. 


PART  YII. 

% ~== 


OF  THE  THORAX. 

BEFORE  the  thorax  is  described,  it  will  be  in  order  to 
consider  the 

Mammae; 

Or  those  glandular  bodies,  situated  on  the  anterior  part 
of  it,  which,  in  females,  are  destined  to  the  secretion  of 
milk. 

These  glands  lie  between  the  skin  and  the  pectoral  mus- 
cles, and  are  attached  to  the  surfaces  of  those  muscles  by 
cellular  membrane. 

They  are  of  a circular  form;  and  consist  of  a whitish 
firm  substance,  divisible  into  small  masses  or  lobes,  which 
are  composed  of  smaller  portions  or  lobuli.  Between  these 
glandular  portions  a great  deal  of  adipose  matter  is  so  dif- 
fused, that  it  constitutes  a considerable  part  of  the  bulk  of 
the  mammae. 

VOL.  II. 


F 


42 


Mamma. 


The  gland  however,  varies  greatly  in  thickness  in  the 
same  person  at  different  periods  of  life. 

The  mammse  become  much  enlarged  about  the  age  of 
puberty.  They  are  also  very  large  during  pregnancy  and 
lactation;  but  after  the  period  of  childbearing,  they  dimi- 
nish considerably.  They  are  supplied  with  blood  by  the 
external  and  internal  mammary  arteries,  the  branches  of 
which  enter  them  irregularly  in  several  different  places. 

The  veins  correspond  with  the  arteries. 

From  the  small  glandular  portions  that  compose  the 
mamma,  fine  excretory  tubes  arise,  which  unite  together 
and  form  the  great  lactiferous  ducts  of  the  gland.  These 
ducts  proceed  in  a radiated  manner  from  the  circumfe- 
rence to  the  center,  and  terminate  on  the  surface  of  the 
nipple. 

They  are  commonly  about  fifteen  in  number,  and  vary 
considerably  in  size:  the  largest  of  them  being  more  than 
one  sixth  of  an  inch  in  diameter. 

They  can  be  very  readily  injected  by  the  orifices  of  the 
nipple,  from  a pipe  filled  with  mercury,  in  subjects  who 
have  died  during  lactation  or  pregnancy;  but  they  are  very 
small  in  subjects  of  a different  description. 

It  has  been  asserted,  by  respectable  anatomists,  that 
these  ducts  communicate  freely  with  each  other;  but  they 
do  not  appear  to  do  so:  each  duct  seems  to  be  connected 
with  its  proper  branches  only. 

Haller  appears  to  have  entertained  the  remarkable  sen- 
timent, that  some  of  the  ducts  originated  in  the  adipose 
matter  about  the  gland,  as  well  as  in  the  glandular  sub- 
stance.* 

The  papilla,  or  nipple,  in  which  these  ducts  terminate, 
is  in  the  center  of  the  mamma:  it  consists  of  a firm  elastic 

* Elementa  Physiologic  Tom.  7,  Pars  11.  pag:  7- 


Marnmce.  43 

substance,  and  is  nearly  cylindrical  in  form.  It  is  rendered 
tumid  by  irritation,  and  by  certain  emotions. 

The  lactiferous  ducts  terminate  upon  its  extremity. 
When  it  is  elongated,  they  can  freely  discharge  their  con- 
tents; but  when  it  contracts,  this  discharge  is  impeded. 

The  skin  immediately  around  the  nipple  is  of  a bright 
red  colour  in  virgins  of  mature  age.  In  pregnant  women 
it  is  sometimes  almost  black;  and  in  women  who  have  borne 
children  it  is  often  brownish.  It  abounds  with  sebaceous 
glands,  which  form  small  eminences  on  its  surface. 

This  gland  exists  in  males,  although  it  is  very  small. 
In  boys,  soon  after  birth,  it  has  often  been  known  to 
tumify  and  become  very  painful,  in  consequence  of  the 
secretion  and  accumulation  of  a whitish  fluid,  which  can 
be  discharged  by  pressure.  It  also  sometimes  swells  and 
is  painful,  in  males  at  the  age  of  puberty. 

There  have  been  some  instances  in  which  it  has  secre- 
ted milk  in  adult  males;  and  a few  instances  also  in  which 
it  has  been  affected  with  cancer,  in  the  same  sex. 

The  mamma  is  plentifully  supplied  with  absorbent  ves- 
sels, which  pass  from  it  to  the  lymphatic  glands  in  the 
axilla. 

Its  nerves  are  principally  derived  from  the  great  plexus 
formed  by  the  nerve.s  of  the  arm. 


44 


CHAPTER  I. 

OF  THE  GENERAL  CAVITY  OF  THE  THORAX. 

SECTION  I. 

Of  the  form  of  the  Cavity  of  the  Thorax. 

1 HE  osseous  structure  of  the  thorax  is  described  in 
vol.  I,  page  88.  The  cavity  is  completed  by  the  intercostal 
muscles,  which  close  the  vacuities  between  the  ribs;  and 
by  the  diaphragm,  which  fills  up  the  whole  space  included 
within  its  lower  margin. 

If  we  except  the  apertures  of  the  diaphragm,  which  are 
completely  occupied  by  the  aorta,  the  vena  cava,  and  the 
oesophagus,  &c.  the  only  outlet  of  this  cavity  is  above:  it  is 
formed  by  the  upper  ribs,  the  first  dorsal  vertebra,  and  the 
sternum.  The  figure  of  this  aperture  is  between  that  of 
the  circle  and  the  oval;  but  it  is  made  irregular  by  the  ver- 
tebra, and  by  the  upper  edge  of  the  sternum. 

When  the  superior  extremities  and  the  muscles  appro- 
priated to  them  are  removed,  the  external  figure  of  the 
thorax  is  conical;  but  the  cavity  formed  by  it  is  considerably 
influenced  by  the  spine,  which  protrudes  into  it;  while  the 
ribs,  as  they  proceed  from  the  spine,  curve  backwards, 
and  thus  increase  its  prominency  in  the  cavity. 

The  diaphragm  has  a great  effect  upon  the  figure  of  the 
cavity  of  the  thorax.  It  protrudes  into  it  from  below,  with 
a convexity  of  such  form  that  it  has  been  compared  to  an 
inverted  bowl;  so  that,  although  it  arises  from  the  lower 
margin  of  the  thorax,  the  central  parts  of  it  are  nearly  as 
high  as  the  fourth  rib. 


Pleurce. 


45 


The  position  of  the  diaphragm  is  also  oblique.  The  an- 
terior porti  n of  its  margin,  being  connected  to  the  seventh 
and  eighth  ribs,  is  much  higher  than  the  posterior  portion, 
which  is  attached  to  the  eleventh  and  twelfth. 

In  consequence  of  the  fgure  and  position  of  the  dia- 
phragm, the  form  of  the  cavity  of  the  thorax  resembles 
that  of  the  hoof  of  the  ox  when  its  posterior  part  is  pre- 
sented forwards. 

SECTION  II. 

Of  the  arrangement  of  the  Pleura. \ 

THE  thorax  contains  the  two  lungs  and  heart,  as  well 
as  several  very  important  parts  of  smaller  size. 

The  lungs  occupy  the  greatest  part  of  the  cavity;  and  to 
each  of  them  is  appropriated  a complete  sac,  called  Pleura , 
which  is  so  arranged  that  it  covers  the  surface  of  the  lungs, 
and  is  continued  from  it  to  the  contiguous  surface  of  the 
thorax,  which  it  lines.  After  covering  the  lung,  it  is  ex- 
tended from  it  to  the  spine  posteriorly,  arid  the  sternum 
anteriorly:  so  that  in  tracing  the  pleura  in  a circular 
direction,  if  you  begin  at  the  sternum,  it  proceeds  on 
the  inside  of  the  ribs  to  the  spine;  at  the  spine  it  leaves 
the  surface  of  the  thorax,  and  proceeds  directly  forwards 
towards  the  sternum.  In  its  course  from  the  spine  to 
the  sternum,  it  soon  meets  with  the  great  branch  of  the 
windpipe  and  the  bloodvessels,  which  go  to  the  lung: 
it  continues  on  these  vessels  and  round  the  lung  until 
it  arrives  at  the  anterior  side  of  the  vessels,  when  it 
again  proceeds  forwards  until  it  arrives  at  the  sternum. 
Each  sac  being  arranged  in  the  same  way,  there  is  a part 
of  each  extended  from  the  spine  to  the  sternum.  These 
two  laminae  form  the  great  vertical  septum  of  the  thorax, 
called  Mediastinum.  They  are  situated  at  some  distance 


46 


Mediastinum. 


from  each  other;  and  the  heart,  with  its  investing  mem- 
brane or  pericardium,  is  placed  between  them. 

The  pericardium  is  also  a complete  sac  or  bladder, 
which,  after  covering  perfectly  the  surface  of  the  heart,  is 
extended  from  it  so  as  to  form  a sac,  which  lies  loose  about 
it,  and  appears  to  contain  it.  This  loose  portion  adheres 
to  those  parts  of  the  laminae  of  the  mediastinum  with 
which  it  is  contiguous;  and  thus  three  chambers  are  form- 
ed within  the  cavity  of  the  thorax:  one  for  each  lung,  and 
one  for  the  heart. 

The  two  laminae  of  the  pleura,  which  constitute  the 
mediastinum,  are  at  different  distances  from  each  other,  in 
different  places.  At  the  upper  part  of  the  thorax,  they  ap- 
proach each  other  from  the  internal  edges  of  the  first  ribs; 
and,  as  these  include  a space  which  is  nearly  circular,  the 
vacuity  between  these  laminae  is  necessarily  of  that  form, 
at  its  commencement  above. 

Here  therefore  is  a space  between  them  above,  which 
is  occupied  by  the  great  transverse  vein  that  carries  the 
blood  of  the  left  subclavian  and  the  left  internal  jugular 
to  the  superior  cava;  by  the  trachea;  by  the  oesophagus; 
and  by  the  subclavian  and  carotid  arteries,  as  they  rise 
from  the  curve  of  the  aorta.  This  space  is  bounded  below 
by  the  above  mentioned  curve  of  the  aorta. 

The  heart  and  pericardium  are  so  placed  that  there  is  a 
small  distance  between  them  and  the  sternum:  in  this 
space  the  two  laminae  of  the  mediastinum  are  very  near  to 
each  other;  and  cellular  substance  intervenes  between 
them.  This  portion  of  the  mediastinum  is  called  the  An- 
terior Mediastinum. 

Posteriorly,  the  heart  and  pericardium  are  also  at  a 
small  distance  from  the  spine;  and  here  the  laminae  of  the 
mediastinum  are  at  a greater  distance  from  each  other,  and 
form  a long  narrow  cavity  which  extends  down  the  thorax 


Preparation  of  the  Thorax.  47 

in  front  of  the  vertebrae:  this  is  called  the  Posterior  Medi- 
astinum. It  contains  a considerable  portion  of  the  aorta  as 
it  descends  from  its  curve,  the  oesophagus,  the  thoracic 
duct,  and  the  vena  azygos.  The  aorta  is  in  contact  with 
the  left  lamina,  and  can  often  be  seen  through  it  when  the 
left  lung  is  lifted  up. 

The  oesophagus  is  in  contact  with  the  right  lamina:  in 
its  progress  downwards,  it  inclines  to  the  left  side  and  is 
advanced  before  the  aorta. 

The  vena  azygos  appears  posterior  to  the  oesophagus: 
it  proceeds  upwards  until  it  is  as  high  as  the  right  branch 
of  the  windpipe:  here  it  bends  forward,  round  that  branch, 
and  opens  into  the  superior  cava,  before  that  vein  opens 
into  the  right  auricle. 

The  thoracic  duct  proceeds  upwards  from  below,  lying 
in  the  spine  between  the  aorta  and  the  vena  azygos,  until 
the  beginning  of  the  curve  of  the  aorta,  when  it  inclines  to 
the  left,  proceeding  towards  the  place  of  its  termination. 

The  formation  of  the  mediastinum,  and  the  arrangement 
of  the  pleura,  as  well  as  the  connexion  of  these  mem- 
branes with  the  parts  contained  in  the  thorax,  may  be 
studied  advantageously,  after  the  subject  has  been  pre- 
pared in  the  manner  now  to  be  described. 

Take  away,  from  each  side,  the  five  ribs  which  are 
situated  between  the  first  and  last  true  ribs,  by  sepa- 
rating their  cartilages  from  the  sternum,  and  their 
heads  from  the  spine;  so  that  the  great  cavities  of  the 
thorax  may  be  laid  open. 

The  precise  course  of  the  mediastinum  is  thus  rendered 
obvious;  and  the  sternum  may  now  be  divided  with  a 
saw  throughout  its  whole  length  in  the  same  direction; 
so  that  the  division  of  the  bone  may  correspond  with  the 
space  between  the  laminae  of  the  mediastinum. 


48 


Preparation  of  the  Thorax. 

Separate  the  portions  of  the  sternum  cautiously,  so  as  to 
avoid  lacerating  the  laminae  of  the  mediastinum;  and 
keep  them  separate,  while  the  trachea  is  dissected  from 
the  neck  into  the  cavity  of  the  thorax;  the  great  trans- 
verse vein  and  the  descending  cava  are  dissected  to 
the  pericardium;  and  the  left  carotid  artery,  with  the 
right  subclavian  and  carotid,  are  dissected  to  the  curve 
of  the  aorta,  taking  care  not  to  destroy  the  laminae  of 
the  mediastinum. 

After  this  preparation  the  upper  space  between  the  laminae 
of  the  mediastinum  can  be  examined;  and  the  relative 
situation  of  the  trachea  and  the  great  vessels  in  it  can 
be  understood.  The  anterior  mediastinum  can  also  be 
studied:  the  root  of  each  lung,  or  its  connexion  with 
the  mediastinum,  may  be  seen  perfectly;  and  the  pre- 
cise situation  of  the  lung,  in  its  proper  cavity,  may  be 
well  conceived. 

After  this,  while  the  portions  of  the  sternum  are  separa- 
ted, the  pericardium  may  be  opened,  and  the  heart 
brought  into  view:  the  attachment  of  the  pericardium 
to  the  mediastinum,  and  to  the  diaphragm,  may  be  seen 
with  advantage  in  this  situation.  The  portions  of  the 
sternum  may  now  be  detached  from  the  ribs,  with  which 
they  remain  connected;  and  further  dissection  may  be 
performed  to  examine  the  posterior  mediastinum  and 
its  contents,  and  the  parts  which  constitute  the  roots  of 
the  lungs. 


49 


CHAPTER  II. 

OF  THE  HEART  AND  THE  PERICARDIUM,  AND  THE  GREAT 
VESSELS  CONNECTED  WITH  THE  HEART. 

SECTION  I. 

Of  the  Pericardium . 

T HE  heart  is  inclosed  by  a membranous  sac,  which,  up- 
on a superficial  view,  seems  only  connected  with  its  great 
vessels;  but  which,  in  fact,  adheres  closely  to  the  whole 
of  its  surface.  From  this  surface  it  is  extended  to  those 
vessels;  from  which  it  proceeds,  after  the  manner  of  the 
reflected  membranes,  and  forms  an  inclosure  that  lies 
loosely  about  the  heart.  If  it  were  dissected  from  the 
heart,  without  laceration  or  wounding,  it  would  be  an 
entire  sac. 

The  pericardium,  thus  arranged,  is  placed  between  the 
two  laminse  of  the  mediastinum,  and  adheres  firmly  to 
them  where  they  are  contiguous  to  it:  it  also  adheres 
firmly  to  the  diaphragm  below,  and  thus  preserves  the 
heart  in  its  proper  position. 

The  figure  of  the  pericardium,  when  it  is  distended,  is 
somewhat  conical;  the  base  being  on  the  diaphragm.  The 
cavity  formed  by  it  is  larger  than  the  heart  after  death, 
but  it  is  probable  that  the  heart  nearly  fills  it  during  life; 
for,  when  this  organ  is  distended  by  injection,  it  often  oc*- 
cupies  the  whole  cavity  of  the  pericardium. 

The  pericardium  is  composed  of  two  lamina:  the  inter- 
nal of  which  covers  the  heart,  as  has  been  already  descri- 
bed; while  the  external  merely  extends  over  the  loose  por- 
Vol.  IT,  G 


50 


l'he  Heart. 


tion  of  the  other,  and  blends  itself  with  the  mediastinum, 
where  that  membrane  invests  the  great  vessels. 

The  internal  surface  of  the  pericardium  is  very  smooth 
and  polished;  and  in  the  living  subject  is  constantly  moist- 
ened with  a fluid,  which  is  probably  effused  from  the  ex- 
halent  vessels  on  its  surface. 

The  quantity  of  this  fluid  does  not  commonly  exceed 
two  drams;  but  in  cases  of  disease  it  sometimes  amounts 
to  man)'  ounces.*  It  is  naturally  transparent,  but  slightly 
tinged  with  red  in  children,  and  yellow  in  old  persons.  It 
is  often  slightly  tinged  with  red  in  persons  who  have  died 
by  violence. 

SECTION  II. 

Of  the  Heart. 

THE  great  organ  of  the  circulation  consists  of  muscular 
libres,  which  are  so  arranged  that  they  give  it  a conical 
form,  and  compose  four  distinct  cavities  within  it. 

Two  of  these  cavities,  which  are  called  Auricles , receive 
the  contents  of  the  veins;  the  other  two  communicate  with 
the  arteries,  and  are  called  Ventricles. 

The  auricles  form  the  basis  of  the  cone;  the  ventricles 
the  body  and  apex. 

The  structure  of  the  auricles  is  much  less  firm  than  that 
of  the  ventricles,  and  consists  of  a smaller  proportion  of 
muscular  fibres.  They  appear  like  appendages  of  the  heart, 
Avhile  the  ventricles  compose  the  body  of  the  viscus. 

' The  pericardium  has  been  so  distended,  by  effusion  in  dropsy,  that  it 
lias  formed  a tumor,  protruding  on  the  neck  from  under  the  sternum. 
This  tumor  had  a strong  pulsating  motion.  It  disappeared  completely 
when  the  other  hydropic  symptoms  were  relieved. 


Connexions  of  the  Heart.  5 1 

The  ventricles  are  very  thick,  and  are  composed  of 
muscular  fibres  closely  compacted. 

The  figure  of  the  heart  is  not  regularly  conical;  for 
a portion  of  it,  extending  from  the  apex  to  the  base,  is 
flattened;  and  in  its  natural  position,  this  flat  part  of  the 
surface  is  downwards. 

It  is  placed  obliquely  in  the  body;  so  that  its  base  pre- 
sents backward  and  to  the  right,  and  its  apex  forward  and 
to  the  left. 

Notwithstanding  this  obliquity,  the  terms  right  and  left 
axe  applied  to  the  different  sides  of  the  heart,  and  to  the 
different  auricles  and  ventricles;  although  they  might,  with 
equal  propriety,  be  called  anterior  and  posterior. 

The  two  great  veins,  called  Fence  Cavce , which  bring  the 
blood  from  every  part  of  the  body,  open  into  the  right 
auricle  from  above  and  below;  the  right  auricle  opens 
into  the  right  ventricle;  and  from  this  ventricle  arises  the 
artery  denominated  Pulmonary , which  passes  to  the  lungs. 

The  Pulmonary  Veins , which  bring  back  the  blood  from 
the  lungs,  open  into  the  left  auricle:  this  auricle  opens  into 
the  left  ventricle;  and  from  this  ventricle  proceeds  the 
Aorta , or  great  artery,  which  carries  blood  to  every  part 
of  the  body. 

The  heart  is  preserved  in  its  position  1st,  by  the  vense  ca- 
vse,  which  are  connected  to  all  the  parts  to  which  they  are 
contiguous  in  their  course;  2d,  by  the  vessels  which  pass 
between  it  and  the  lungs,  which  are  retained  in  a particular 
position  by  the  mediastinum ; 3d,  by  the  aorta,  which  is  at- 
tached to  the  mediastinum  in  its  course  downwards,  after 
making  its  great  curve;  and  4th,  by  the  pericardium,  which 
is  attached  to  the  great  vessels  and  to  the  mediastinum.  Bv 
these  different  modes  the  basis  of  the  heart  is  fixed,  while 


52 


Right  Auricle. 

its  body  and  apex  are  perfectly  free  from  attachment,  and 
only  contiguous  to  the  pericardium. 

The  external  surface  of  the  heart,  being  formed  by  the 
pericardium,  is  very  smooth:  under  this  surface  a large 
quantity  of  fat  is  often  found. 

The  two  auricles  are  contiguous  to  each  other  at  the 
base,  and  are  separated  by  a partition  which  is  common  to 
both. 

The  Right  Auricle  originates  from  the  junction  of  the 
two  venae  cavae.  These  veins  are  united  at  some  distance 
behind  the  right  ventricle,*  and  are  dilated  anteriorly  into 
a sac  or  pouch,  which  is  called  the  Sinus , and  extends  to 
the  right  ventricle,  to  which  it  is  united. 

The  upper  part  of  this  pouch,  or  sinus,  forms  a point 
with  indented  edges,  which  is  detached  from  the  ventricle, 
and  lies  loose  on  the  right  side  of  the  aorta.  This  point 
has  some  resemblance  to  the  ear  of  a dog,  from  which  cir- 
cumstance the  whole  cavity  has  been  called  auricle;  but  by 
many  persons  the  cavity  is  considered  as  consisting  of  two 
portions:  the  Auricle , strictly  speaking;  and  the  Sinus  Ve- 
nosus , above  described:  they  however  form  but  one  cavity. 

This  portion  of  the  heart,  or  Right  Auricle , is  of  an 
irregular  oblong  figure.  In  its  posterior  surface  it  is 
indented;  for  the  direction  of  the  two  cavae,  at  their 
junction,  is  not  precisely  the  same;  but  they  form  an 
angle,  which  causes  this  indentation.  The  anterior  por- 
tion of  the  auricle,  or  that  which  appears  like  a pouch  be- 
tween the  ventricle  and  the  veins,  is  different  in  its  struc- 
ture from  the  posterior  part,  which  is  strictly  a portion  of 
the  veins.  It  consists  simply  of  muscular  fibres,  which  are 
arranged  in  fasciculi  that  cover  the  whole  internal  surface: 

* In  this  description  the  heart  is  supposed  tp  be  in  its  natural 
position. 


Right  Ventricle.  55 

this  is  also  the  case  with  the  point,  or  that  part  which  is 
strictly  called  auricle. 

These  fasciculi  are  denominated  Musculi  Pectinatif rom 
their  resemblance  to  the  teeth  of  a comb. 

That  part  of  the  internal  surface,  which  is  formed  by 
the  septum,  is  smooth;  and  the  whole  is  covered  by  a de- 
licate membrane. 

On  the  surface  of  the  septum,  below  the  middle,  is  an 
oval  depression,  which  has  a thick  edge  or  margin:  this  is 
called  the  Fossa  Ovalis.  In  the  fcetal  heart,  it  was  the 
Foramen  Ovale , or  aperture  which  forms  the  communica- 
tion between  the  two  auricles. 

Near  this  fossa  is  a large  semilunar  plait,  or  valve, 
with  its  points  and  concave  edge  uppermost,  and  convex 
edge  downwards.  It  was  described  by  Eustachius,  and, 
therefore,  is  called  the  Valve  of  Eustachius. 

Anterior  to  this  valve,  and  near  the  union  of  the  auricle 
and  ventricle,  is  the  orifice  of  the  proper  vein  of  the  heart, 
or  the  coronary  vein.  This  orifice  is  covered  by  another 
semilunar  valve,  which  is  sometimes  reticulated. 

The  aperture,  which  forms  the  communication  between 
the  right  auricle  and  right  ventricle,  is  about  an  inch  in 
diameter.  From  its  whole  margin  arises  a valvular  ring, 
or  duplicature  of  the  membrane  lining  the  surface:  this 
circular  valve  is  divided  into  three  angular  portions,  which 
are  called  Valvulce  Tricuspides.  From  their  margins  pro- 
ceed a great  number  of  fine  tendinous  threads,  which  are 
connected  to  a number  of  distinct  portions  of  muscular 
substance,  which  arise  from  the  ventricle. 

The  Right  Ventricle , when  examined  separate  from  the 
other  parts  of  the  heart,  is  rather  triangular  in  its  figure. 
It  is  composed  entirely  of  muscular  fibres  closely  com- 
pacted; and  is  much  thicker  than  the  auricle,  although  not 


54  Right  Ventricle . 

so  thick  as  the  other  ventricle.  Its  internal  surface  is 
composed  of  bundles  or  columns  of  fleshy  fibres,  which  are 
of  various  thickness  and  length.  Some  of  these  columns 
arise  from  the  ventricle,  and  are  connected  with  the  ten- 
dinous threads,  which  are  attached  to  the  margins  of  the 
tricuspid  valves:  the  direction  of  them  is  from  the  apex  of 
the  heart  towards  the  base.  Others  of  the  columns  arise 
from  one  part  of  the  surface  of  the  ventricle,  and  are  in- 
serted into  another  part.  A third  species  are  attached  to 
the  ventricle  throughout  their  whole  length,  forming 
ridges  or  eminences  on  it.  The  columns  of  the  two  last 
described  species  are  very  numerous.  They  present  an 
elegant  reticulated  surface  when  the  ventricle  is  laid  open, 
and  appear  also  to  occupy  a considerable  portion  of  the 
cavity  of  the  heart,  which  some  of  them  run  across  in  every 
direction  near  the  apex.  They  are  all  covered  by  a mem- 
brane continued  from  the  auricle  and  the  tricuspid  valves; 
but  this  membrane  appears  more  delicate  and  transparent 
in  the  ventricle  than  it  is  in  the  auricle. 

A portion  of  the  internal  surface  of  the  ventricle,  which 
is  to  the  left,  is  much  smoother  and  less  fasciculated  than 
the  rest:  it  leads  to  the  orifice  of  the  pulmonary  artery, 
which  arises  from  it  near  the  basis  of  the  ventricle.  This 
artery  is  very  conspicuous,  externally,  at  the  basis  of  the 
heart. 

It  is  very  evident,  upon  the  first  inspection  of  the  heart, 
that  the  valvulse  tricuspides  will  permit  the  blood  to  flow 
from  the  auricle  to  the  ventricle;  but  must  rise  and  close 
the  orifice,  and  thereby  prevent  its  passage  back  again, 
when  the  ventricle  contracts. 

The  use  of  the  tendinous  threads,  which  connect  the 
valves  to  the  fleshy  columns,  is  also  very  evident:  the 
valve  is  supported  by  this  connexion,  and  prevented  from 


Right  Ventricle.  55 

yielding  to  the  pressure  and  opening  a passage  into  the 
auricle.  The  blood,  therefore,  upon  the  contraction  of  the 
ventricle,  is  necessarily  forced  into  the  pulmonary  artery; 
the  passage  to  which  is  now  perfectly  free.  Into  this 
artery  the  membrane  lining  the  ventricle  seems  continued; 
but  immediately  within  the  orifice  of  the  artery  it  is  formed 
into  three  semicircular  folds,  each  of  which  adheres  to  the 
surface  of  the  artery  by  its  circumference,  while  the  edge 
constituting  its  diameter  is  loose.  In  the  middle  of  this 
loose  edge,  is  a small  firm  tubercle,  called  Corpusculum 
Arantii,*  which  adds  to  the  strength  of  the  valve.  Each, 
of  these  valves,  by  its  connexion  with  the  artery,  forms  a 
sac  or  pocket,  the  orifice  of  which  opens  forward  towards 
the  course  of  the  artery,  and  the  bottom  of  it  presents  to- 
wards the  ventricle.  Blood  will,  therefore,  pass  from  the 
ventricle  into  the  artery,  and  along  it,  without  filling  these 
sacs;  and  on  the  contrary,  in  this  course,  will  compress 
them  and  keep  them  empty.  If  it  moves  in  the  artery 
towards  the  heart,  it  will  necessarily  fill  these  sacs,  and 
press  the  semicircular  portions  from  the  sides  of  the 
artery  against  each  other;  by  this  means  a partition,  or 
septum,  consisting  of  three  portions,  will  be  formed  be- 
tween the  artery  and  the  heart,  which  will  always  exist 
when  the  artery  compresses  (or  acts  upon)  its  contents.  It 
is  demonstrable,  by  injecting  wax  into  the  artery,  in  a re- 
trograde direction,  that  these  valves  do  not  form  a flat 
septum,  but  one  which  is  convex  towards  the  heart,  and 
concave  towards  the  artery;  and  that  this  convexity  is 
composed  of  three  distinct  parts,  each  of  which  is  convex. 
At  the  place  where  these  valves  are  fixed,  the  artery  bulges 
out  when  distended  by  a retrograde  injection.  The  en- 


* After  Arantius,  a professor  at  Bologna,  who  first  described  it 


56 


Left  Auric/e. 

largements  thus  produced  are  called  the  Sinuses  of  Val- 
salva, after  the  anatomist  who  first  described  them.  The 
valves  are  called  Semilunar ; and,  although  they  are  form- 
ed by  a very  thin  membrane,  they  are  very  strong. 

The  Left  Auricle  is  situated  on  the  left  side  of  the  basis 
of  the  heart.  It  originates  from  the  junction  of  the  four 
pulmonarj'  veins;  two  of  which  come  from  each  side  of 
the  thorax,  and  appear  to  form  a large  part  of  it.  It  is 
nearly  of  a cubic  form;  but  has  also  an  angular  portion, 
which  constitutes  the  proper  auricle,  that  proceeds  from 
the  upper  and  left  part  of  the  cavity,  and  is  situated  on  the 
left  side  of  the  pulmonary  artery. 

This  auricle  is  lined  by  a strong  membrane,  from  which 
the  valves  between  it  and  the  ventricle  originate:  but  it 
has  no  fleshy  columns  or  musculi  pectinati,  except  in  the 
angular  process  properly  called  auricle. 

These  valves,  and  the  orifice  communicating  with  the 
ventricle,  resemble  those  which  have  been  already  describ- 
ed between  the  right  auricle  and  ventricle;  but  with  this 
difference,  that  the  valvular  ring  is  divided  into  two  por- 
tions only,  instead  of  three,  which  are  called  Valvulce 
Mitrales.  The  tendinous  threads,  which  are  connected  to 
the  muscular  columns,  are  also  attached  to  these  valves, 
as  in  the  case  of  the  right  auricle. 

These  valves  admit  the  passage  of  blood  from  the 
auricle  into  the  ventricle,  but  completely  prevent  its  re- 
turn when  the  ventricle  contracts.  One  of  them  is  so 
situated  that  it  covers  the  mouth  of  the  aorta  while  the 
blood  is  flowing  into  the  ventricle,  and  leaves  that  orifice 
open  when  the  ventricle  contracts,  and  the  passage  to  the 
auricle  is  closed. 

The  Left  Ventricle  is  situated  posteriorly,  anti  to  die 


Muscular  Fibres  of  the  Heart.  57 

left  of  the  Right  Ventricle:  its  figure  is  different,  for  it  is 
rather  conical,  and  it  is  also  longer. 

The  internal  surface  of  this  ventricle  resembles  that  of 
the  right  ventricle;  but  the  columns  carnese  are  stronger 
and  larger. 

On  the  right  side  of  this  ventricle  is  the  mouth  of  the 
aorta.  The  surface  of  the  ventricle  near  this  opening  is 
smooth. 

The  cavity  of  this  ventricle  is  supposed  to  be  smaller 
than  that  of  the  right:  but  the  amount  of  the  difference  has 
not  been  accurately  ascertained. 

This  ventricle  must  have  much  more  force  than  the 
right,  as  its  parietes  are  so  much  thicker.  Their  thickness 
often  exceeds  half  an  inch. 

The  difference  in  the  strength  of  the  two  ventricles 
probably  corresponds  with  the  difference  between  the  ex- 
tent of  the  pulmonary  artery  and  the  aorta. 

The  thickness  of  the  septum  between  the  ventricles 
is  thicker  than  the  sides  or  parietes  of  the  right  ventricle, 
and  less  thick  than  those  of  the  left. 

The  muscular  fibres  of  the  heart  are  generally  less 
florid  than  those  of  the  voluntary  muscles:  they  are  also 
more  closely  compacted  together.  The  direction  of  many 
of  them  is  oblique  or  spiral;  but  this  general  arrangement 
is  very  intricate:  it  is  such,  however,  that  the  cavities  of 
the  heart  are  lessened,  and  probably  completely  obliterated, 
by  the  contraction  of  these  fibres.* 

The  external  surface  of  the  heart  is  covered  by  that 
portion  of  the  pericardium  which  adheres  to  it.  Adipose 
matter  is  often  deposited  between  this  membrane  and  the 

* Mr.  Home  lias  given  a precise  description  of  the  muscular  fibres 
of  the  heart  in  his  Croonian  Lecture.  London  Philosophical  Transac- 
tions for  1795,  part  1,  page  215. 

VOL.  II. 


Ii 


58  Coronary  Vessels,  &?c. 

muscular  surface;  being  distributed  irregularly  in  various 
places. 

This  membrane  is  continued  from  the  surface  of  the 
ventricles  over  that  of  the  auricles.  When  it  is  dissected 
off  from  the  place  of  their  junction,  these  surfaces  appear 
very  distinct  from  each  other. 

The  proper  bloodvessels  of  the  heart  appear  to  be  ar- 
ranged in  conformity  to  the  general  laws  of  the  circula- 
tion, and  are  very  conspicuous  on  the  surface.  There  are 
two  arteries  which  arise  from  the  aorta  immediately  after 
it  leaves  the  heart,  so  that  their  orifices  are  covered  by 
two  of  the  semilunar  valves.  One  of  these  passes  from  the 
aorta  between  the  pulmonary  artery  and  the  right  auricle, 
and  continues  in  a circular  course  in  the  groove  between 
the  right  auricle  and  the  right  ventricle,  and  sends  off  its 
principal  branches  to  the  right  side  of  the  heart. 

The  other  artery  of  the  heart  passes  between  the  pul- 
monary artery  and  the  left  auricle.  It  divides  into  two 
branches:  one,  which  is  anterior,  passes  to  a groove  on 
the  surface,  corresponding  to  the  septum  between  the  two 
ventricles,  and  continues  on  it  to  the  apex  of  the  heart, 
sending  off  branches  in  its  course;  another,  which  is  pos- 
terior and  circumflex,  passes  between  the  left  auricle  and 
ventricle. 

The  great  vein  of  the  heart  opens  into  the*under  side  of 
the  right  auricle,  as  has  been  already  mentioned:  the  main 
trunk  of  this  vein  passes  for  some  distance  between  the 
left  auricle  and  ventricle.^ 

It  was  asserted  by  Vieussens  at  an  early  period,  in  the  last  century, 
and  soon  afterwards  by  Thebesius,  a German  professor,  that  there 
were  a number  of  small  orifices  in  the  texture  of  the  heart,  which  open- 
ed into  the  different  cavities  on  both  sides  of  it 


This 


The  Great  Vessels. 


59 


From  the  course  of  these  different  vessels  round  the 
basis  of  the  ventricles  of  the  heart,  they  are  generally 
called  Coronary  Vessels:  the  arteries  are  denominated, 
from  their  position,  Right  and  Left  Coronary. 

The  nerves  of  the  heart  come  from  the  cardiac  plexus, 
which  is  composed  of  threads  derived  from  the  intercostal 
or  great  sympathetic  nerves,  and  the  nerves  of  the  eighth 
pair. 

SECTION  III. 

Of  the  Aorta , the  Pulmonary  Artery  and  Veins , and 
the  Vence  Caves;  at  their  commencement. 

THE  two  great  arteries,  which  arise  from  the  heart, 
commence  abruptly,  and  appear  to  be  extremely  different 
in  their  composition  and  structure  from  the  heart. 

This  assertion  of  a fact  so  difficult  to  reconcile  with  the  general  prin- 
ciples of  the  circulation,  was  received  with  great  hesitation:  and  al- 
though it  was  confirmed  by  some  very  respectable  anatomists  of  the  last 
century,  it  was  denied  by  others.  Some  of  the  anatomists  of  the  present 
day  have  denied  the  existence  of  these  orifices,  and  some  others  have 
neglected  them  entirely. 

Thejsubject  has  lately  been  brought  forward  in  the  London  Philoso’- 
phical  Transactions  for  1798,  Part  I,  by  a very  respectable  anatomist, 
Mr.  Abernethy,  who  states  that  he  has  often  passed  a coarse  waxen 
injection  from  the  proper  arteries  and  veins  of  the  heart  into  all  the 
cavities  of  that  organ,  and  particularly  into  the  Left  Ventricle.  Hut  it  ~eas 
only  in  subjects  -with  diseased  httigs  that  this  -was  practicable. 

The  existence  of  this  communication  between  the  coronary  vessels 
and  the  great  cavities  of  the  heart  seems  therefore  to  be  proved.  The 
easy  demonstration  in  such  subjects  is  ingeniously  referred  by  Mr. 
Abernethy  to  the  obstruction  of  the  circulation  in  the  lungs-’  and  he 
regards  the  communication  as  a provision  enabling  the  coronary  ves- 
sels to  unload  themselves,  when  the  coronary  vein  cannot  discharge" 
freely  into  the  right  auricle. 


Aorta. 


They  are  composed  of  a substance,  which  has  a whitish 
color  and  very  dense  texture,  and  is  very  elastic  as  well  as 
firm  and  strong. 

When  the  pericardium  is  removed,  these  arteries  ap- 
pear to  proceed  together  from  the  upper  part  of  the  basis 
of  the  heart:  the  pulmonary  artery  being  placed  to  the  left 
of  the  aorta  with  the  left  auricle  on  the  left  side  of  it,  and 
the  right  auricle  on  the  right  side  of  the  aorta.  The  pul- 
monary artery  arises  from  the  most  anterior,  and  left  part 
of  the  basis  of  the  right  ventricle,  and  proceeds  obliquely 
backwards  and  upwards;  inclining  gradually  to  the  left  side 
for  about  eighteen  or  twenty  lines;  when  it  divides  into  two 
branches  which  pass  to  the  twro  lungs. 

The  aorta  arises  from  the  left  ventricle,  under  the  origin 
of  the  pulmonary  artery,  and  immediately  proceeds  to  the 
right,  covered  by  that  vessel,  until  it  mounts  up  between 
it  and  the  right  auricle:  it  then  forms  a great  curve,  or 
arch,  which  turns  backward  and  to  the  left,  to  a considera- 
ble distance  beyond  the  pulmonary  artery.  In  this  course, 
it  crosses  the  right  branch  of  the  pulmonary  artery;  and, 
turning  down  in  the  angle  between  it  and  the  left  branch, 
takes  a position  on  the  left  side  of  the  spine. 

The  course  of  this  artery,  from  its  commencement  at 
the  ventricle,  to  the  end  of  the  great  curve  or  arch,  is  ex- 
tremely varied. 

The  uppermost  part  of  the  curve  is  in  the  bottom  of  the 
chamber  formed  by  the  separation  of  the  laminae  of  the 
mediastinum  when  they  join  the  first  rib  on  each  side. 

From  this  part  of  the  curve  three  large  branches  go 
off,  viz.:  one,  which  soon  divides  into  the  carotid  and 
the  subclavian  arteries  of  the  right  side;  a second,  some- 
what smaller,  which  is  the  left  carotid;  and  a third,  which 
is  the  left  subclavian  artery. 


Pulmonary  Artery  and  Veins  and  Vence  Cavce.  6 1 

When  the  heart  and  its  great  vessels  are  viewed  from 
behind,  (after  they  have  all  been  filled  with  injection;  and 
the  pericardium,  mediastinum,  and  windpipe  have  been 
removed,)  the  aorta  appears  first,  descending  behind  the 
other  vessels;  the  pulmonary  artery  then  appears,  dividing 
so  as  to  form  an  obtuse  angle  with  its  two  great  branches, 
each  of  which  divides  again  before  it  enters  the  lung  to 
which  it  is  destined. 

Under  the  main  trunk  of  the  pulmonary  artery  is  the 
left  auricle:  its  posterior  surface  is  nearly  of  a square  form, 
and  each  of  the  pulmonary  veins  proceeds  from  one  of  its 
angles.  These  veins  ramify  in  the  substance  of  the  lungs, 
at  a very  short  distance  from  the  auricle:  the  two  upper- 
most of  them  are  situated  rather  anterior  to  the  branches 
of  the  pulmonary  artery. 

In  this  posterior  view,  the  pulmonary  vessels  of  the 
right  side  cover  a great  part  of  the  right  auricle,  as  it  is 
anterior  to  them.  The  lower  portion  of  the  auricle,  with 
the  termination  of  the  inferior  cava,  is  to  be  seen  below 
them.  Above  them,  the  superior  cava  appears;  and  in 
that  part  of  it,  which  is  immediately  above  the  right 
branch  of  the  pulmonary  artery,  is  the  orifice  of  the  vena 
azygos. 

In  its  natural  situation  in  the  thorax,  the  superior  cava 
is  connected  by  cellular  membrane  to  the  right  lamina  of 
the  mediastinum,  and  supported  by  it.  At  a small  distance 
below  the  upper  edge  of  the  sternum,  it  receives  the  trunk 
formed  by  the  left  subclavian  and  internal  jugular  vein 
which  passes  obliquely  across  the  sternum  below  its  inner 
edge,  in  the  upper  space  between  the  laminae  of  the  medi- 
astinum. 


CHAPTER  III. 


OF  THE  TRACHEA  AND  THE  LUNGS. 

Although  the  principal  part  of  the  windpipe  is 
situated  in  the  neck  above  the  cavity  of  the  thorax,  it  is 
so  intimately  connected  with  the  lungs,  that  it  is  necessary 
to  describe  them  together. 

SECTION  I. 

Of  the  Trachea . 

Trachea  is  the  technical  name  for  the  windpipe,  or 
tube  which  passes  from  the  larynx  to  the  lungs. 

This  tube  begins  at  the  lower  edge  of  the  cricoid  car- 
tilage, and  passes  down  the  neck  in  front  of  the  oesophagus 
as  low  as  the  third  dorsal  vertebra,  when  it  divides  into 
two  branches  called  Bronchia ?,  one  of  which  goes  to  the 
right  and  the  other  to  the  left  lung  and  ramifies  very 
minutely  in  them. 

There  is  in  its  structure  a number  of  flat  cartilaginous 
rings  placed  at  small  distances  from  each  other,  the  edges 
of  which  are  connected  by  membrane  so  that  they  compose 
a tube. 

These  cartilaginous  rings  are  not  complete,  for  they  do 
not  form  more  than  three  fourths  or  four  fifths  of  a circle; 
but  their  ends  are  connected  by  a membrane  which  forms 
the  posterior  part  of  the  tube. 

They  are  not  alike  in  their  size  or  form;  some  of  them 
are  rendered  broader  than  others,  by  the  union  of  two  or 
three  rings  with  each  other,  as  the  uppermost.  The  lower- 
most also  is  broad,  and  has  a form  which  is  accommoda,ted 


Structure  of  the  Trachea.  63 

to  the  bifurcation  of  the  tube.  Their  number  varies,  in  dif- 
ferent persons,  from  fifteen  to  twenty. 

These  rings  may  be  considered  as  forming  a part  of  the 
first  proper  coat  of  the  trachea;  which  is  composed  of 
them,  and  of  an  elastic  membrane  that  occupies  all  the 
interstice  between  them;  so  that  the  cartilages  may  be  re« 
garded  as  fixed  in  this  membrane. 

A similar  arrangement  of  rings  exists  in  the  great 
branches  of  the  bronchise;  but  after  they  ramify  in  the 
lungs,  the  cartilages  are  no  longer  in  the  form  of  rings: 
they  are  irregular  in  their  figures,  and  are  so  arranged  in 
the  membrane  that  they  keep  the  tube  completely  open. 
These  portions  of  cartilage  do  not  continue  throughout 
the  whole  extent  of  the  ramifications;  for  they  become 
smaller,  and  finally  disappear,  while  the  membranous 
tube  continues  without  them,  ramifying  minutely,  and 
probably  forming  the  air  cells  of  the  lungs. 

This  membrane  is  very  elastic:  the  lungs  are  very  elastic 
also;  and  it  is  probable  that  their  elasticity  is  derived  from 
this  membrane. 

On  the  inside  of  this  coat  of  the  trachea  is  an  arrange- 
ment of  muscular  fibres,  which  may  be  called  a muscular 
coat.  It  is  best  seen  by  peeling  off  or  removing  the  inter- 
nal coat  to  be  next  described. 

On  the  membranous  part  of  the  trachea,  where  the  car- 
tilaginous rings  are  deficient,  these  muscular  fibres  run 
evidently  in  a transverse  direction:  in  the  spaces  between 
the  cartilages  their  direction  is  longitudinal.  There  is 
some  reason  to  doubt  whether  these  longitudinal  fibres  are 
confined  altogether  to  the  spaces  between  the  cartilaginous 
rings,  and  attached  only  to  their  edges,  because  there  is  a 
fleshy  substance  on  the  internal  surface  of  the  rings,  which 
appears  to  be  continued  from  the  spaces  between  them. 


64  Black  Glands  on  the  Bronchiee. 

The  internal  coat  of  the  trachea  is  a thin  and  delicate 
membrane,  perforated  with  an  immense  number  of  small 
foramina,  which  are  the  orifices  of  mucous  ducts. 

On  the  surface  of  this  membrane  there  is  an  appearance 
of  longitudinal  fibres  which  are  not  distributed  uniformly 
over  it,  but  run  in  fasciculi  in  some  places,  and  appear  to 
be  deficient  in  others.  These  fasciculi  are  particularly 
conspicuous  in  the  ramifications  of  the  bronchi®  in  the 
lungs. 

On  the  posterior  membranous  portion  of  the  trachea, 
where  the  cartilages  are  deficient,  a considerable  number 
of  small  glandular  bodies  are  placed,  which  are  supposed 
to  communicate  with  the  mucous  ducts  that  open  on  the 
internal  surface.  If  these  bodies  are  removed  from  the 
external  surface  of  this  portion,  and  the  muscular  fibres 
are  also  removed  from  the  internal,  a very  thin  membrane 
only  remains,  which  is  very  different  from  that  which  is 
left  between  the  rings,  when  the  fleshy  substance  is  re- 
moved from  that  situation. 

The  reason  of  the  deficiency  in  the  rings,  at  this  poste- 
rior part,  is  not  very  obvious.  It  continues  in  the  bronchi® 
until  the  form  of  their  cartilages  is  changed  in  the  lungs: 
if  it  were  only  to  accommodate  the  (esophagus,  during  the 
passage  of  food,  there  would  be  no  occasion  for  its  exten- 
sion to  the  bronchi®. 

At  the  bifurcation  of  the  trachea,  and  on  the  bronchi®, 
are  a number  of  black  colored  bodies,  which  resemble 
the  lymphatic  glands  in  form  and  texture.  They  continue 
on  the  ramifications  of  the  bronchi®  some  distance  into  the 
substance  of  the  lungs.  Their  number  is  often  very  consi- 
derable; and  they  vary  in  size  from  three  or  four  lines  in 
diameter  to  eighteen  or  twenty.  As  lymphatic  vessels 
have  been  traced  to  and  from  them  during  their  course 


Root  of  the  Lungs.  65 

to  the  thoracic  duct,  they  are  considered  as  lymphatic 
glands. 

SECTION  II. 

Of  the  Lungs. 

THERE  are  two  of  these  organs:  each  of  which  occu- 
pies one  of  the  great  cavities  of  the  thorax. 

When  placed  together,  in  their  natural  position,  they 
resemble  the  hoof  of  the  ox,  with  its  back  part  forward; 
but  they  are  at  such  a distance  from  each  other,  and  of 
such  a figure,  that  they  allow  the  mediastinum  and  heart 
to  intervene;  and  they  cover  every  part  of  the  heart  ante- 
riorly, except  a small  portion  at  the  apex. 

Each  lung  fills  completely  the  cavity  in  which  it  is 
placed,  and  every  part  of  its  external  surface  is  in  contact 
with  some  part  of  the  internal  surface  of  the  cavity;  but 
when  in  a natural  and  healthy  state,  it  is  not  connected 
with  any  part  except  the  laminae  of  the  mediastinum.  One 
great  branch  of  the  trachea  and  of  the  pulmonary  artery 
pass  from  the  mediastinum  to  each  lung,  and  enter  it  at 
a place  which  is  rather  nearer  to  the  upper  rib  than  to  the 
diaphragm,  and  much  nearer  to  the  spine  than  the  sternum: 
at  this  place  also  the  pulmonary  veins  return  from  the  lung 
to  the  heart. 

These  vessels  are  inclosed  in  a membrane,  which  is  con- 
tinued over  them  from  the  mediastinum,  and  extended 
from  them  to  the  lung.  Thus  covered,  they  constitute  what 
has  been  called  the  Root  of  the  Lung. 

When  their  covering,  derived  from  the  mediastinum,  is 
removed,  the  situation  of  these  vessels  appears  to  be  such 
that  the  bronchi®  are  posterior,  the  branches  of  the  pul- 
monary artery  are  rather  above  and  before,  and  the  veins 
below  and  before  them. 

VOL.  II. 


J 


66  Color  of  the  Lungs. 

Each  of  these  vessels  ramifies  before  it  enters  into  the 
substance  of  the  lungs:  the  bronchise  and  the  branches  of 
the  pulmonary  artery  send  each  a large  branch  downward 
to  the  inferior  part  of  the  lungs,  from  which  the  lower  pul- 
monary veins  pass  in  a direction  nearly  horizontal.  In 
general,  each  of  the  smaller  ramifications  of  the  bronchiae 
in  the  lungs  is  attended  by  an  artery  and  a vein. 

Each  lung  is  divided,  by  very  deep  fissures,  into  por- 
tions which  are  called  Lobes.  The  right  lung  is  composed  of 
three  of  these  lobes,  and  the  left  lung  of  two. 

The  lungs  are  covered,  as  has  been  already  stated, 
with  the  reflected  portion  of  the  pleura  continued  from 
the  mediastinum,  which  is  very  delicate,  and  almost  trans- 
parent. They  have,  therefore,  a very  smooth  surface, 
which  is  kept  moist  by  exudation  from  the  arteries  of  the 
membrane. 

The  Color  of  the  Lungs  is  different  in  different  subjects. 
In  children  they  are  of  a light  red  color;  in  adults  they  are 
often  of  a light  gray;  owing  to  the  deposition  of  a black 
pigment  in  the  substance  immediately  under  the  mem- 
branes which  form  their  external  surface.  Their  color  is 
often  formed  by  a mixture  of  red  and  black.  In  this  case 
they  are  more  loaded  with  blood,  and  the  vessels  of  the 
internal  membranes  being  distended  with  it,  the  red  color 
is  derived  from  them. 

The  black  pigment  sometimes  appears  in  round  spots 
of  three  or  four  lines  in  diameter:  under  the  external 
membrane  it  is  often  in  much  smaller  portions,  and  some- 
times is  arranged  in  lines  in  the  interstices  of  the  lobuli, 
to  be  hereafter  mentioned.  It  is  also  diffused  in  small 
quantities  throughout  the  substance  of  the  lungs. 

The  source  of  this  substance,  and  the  use  of  it,  are 
unknown. 


67 


Structure  of  the  Lungs. 

The  lungs  are  of  a soft  spongy  texture;  and,  In  animals 
that  have  breathed,  they  have  always  a considerable  quan- 
tity of  air  in  them. 

They  consist  of  cells,  which  communicate  with  the 
branches  of  the  trachea  that  ramify  through  them  in 
every  part.  These  cells  are  extremely  small,  and  the 
membranes  which  compose  them  are  so  thin  and  delicate 
that  if  they  are  all  filled  by  an  injection  of  wax,  thrown 
into  the  trachea,  the  whole  cellular  part  of  the  lung  will 
appear  like  a mass  of  wax.  If  a corroded  preparation  be 
made  of  a lung  injected  in  this  manner  with  force,  the 
wax  will  appear  like  a concretion. 

These  effects  of  injection  prove  that  the  membranes  of 
which  the  cells  are  formed  are  very  thin;  and,  of  course, 
that  their  volume  is  very  small  when  compared  with  the 
capacity  of  the  cells. 

In  those  corroded  preparations,  in  which  the  ramifica- 
tions of  the  bronchi®  are  detached  from  the  wax  of  the 
cells,  these  ramifications  become  extremely  small  indeed. 

If  the  lungs  of  the  human  subject,  or  of  animals  of 
similar  construction,  be  examined  when  they  are  inflated, 
their  cellular  structure  will  be  very  obvious,  although 
their  cells  are  so  small  that  they  cannot  commonly  be 
distinguished  by  the  naked  eye.  Each  of  the  extreme  ra- 
mifications of  the  bronchia:  appears  to  be  surrounded  by  a 
portion  of  this  cellular  structure,  which  is  gradually  dis- 
tended when  air  is  blown  into  the  ramification. 

This  cellular  substance  is  formed  into  small  portions  of 
various  angular  figures,  which  are  denominated  Lobuli: 
these  can  be  separated  to  a considerable  extent  from  each 
other.  They  are  covered  by  the  proper  coat  of  the  lungs, 
which  is  extremely  delicate,  and  closely  connected  to  the 
general  covering  derived  from  the  pleura.  Between  the 
lobuli,  when  they  are  in  contact  with  each  other,  there  is 


68 


Structure  of  the  Lungs. 


a portion  of  common  cellular  substance,  which  is  easily 
distinguished  through  the  membrane  covering  the  lungs; 
This  is  very  distinct  from  the  cellular  structure  which 
communicates  with  the  ramifications  of  the  branchiae,  and 
contains  air;  for  it  has  no  communication  with  the  air, 
unless  the  proper  coat  of  the  lungs  be  ruptured.  If  a pipe 
be  introduced  by  a puncture  of  the  external  coat  of  the 
lungs,  and  this  interstitial  cellular  membrane  be  inflated, 
it  will  compress  the  lobuli.  This  cellular  membrane  is 
always  free  from  adipose  matter:  it  may  be  easily  examin- 
ed in  the  lungs  of  the  bullock. 

Upon  the  membranes  which  compose  the  air  cells,  the 
pulmonary  artery  and  vein  ramify  most  minutely;  and  it 
seems  to  have  been  proved  within  the  last  thirty  years,  by 
the  united  labors  of  chemists  and  physiologists,  that  the 
great  object  of  respiration  is  to  effect  a chemical  process' 
between  the  atmospheric  air,  when  taken  into  the  air  cells, 
and  the  blood  which  circulates  in  these  vessels. 

In  addition  to  the  bloodvessels  which  thus  pass  through 
the  substance  of  the  lungs,  there  are  several  smaller  ar- 
teries, denominated  Bronchial , which  arise  either  from 
the  upper  intercostal,  or  from  the  aorta  itself:  they  pass 
upon  the  branchiae,  and  are  distributed  to  the  substance  of 
the  lungs.  The  veins  which  correspond  with  these  arteries 
terminate  ultimately  in  the  vena  azygos. 

The  nerves  of  the  lungs  are  small  in  proportion  to  the 
bulk  of  these  organs.  They  are  derived  principally  from 
the  par  vagum  and  the  intercostal  nerves. 

The  elasticity  of  the  air  cells  of  the  lungs  and  of  the  rami- 
fications of  the  branchiae  which  lead  to  them,  appears  by 
their  rapid  contraction  after  distention,  and  by  the  force 
with  which  they  expel  the  air  which  i3  used  to  inflate 
them  when  taken  out  of  the  thorax. 


69 


The  Thorax  of  the  Foetus. 

In  the  cavity  between  the  laminse  of  the  mediastinum, 
where  they  approach  each  other  from  the  first  ribs,  is  situ- 
ated a substance  which  is  denominated  the 
Thymus-  Gland. 

This  substance  gradually  diminishes  after  birth,  so  that 
in  the  adult  it  is  often  not  to  be  found:  and  when  it  exists 
it  is  changed  in  its  texture,  being  much  firmer,  as  well  as 
greatiy  diminished. 

In  the  foetus  it  is  of  a pale  red  color;  and  during  infan- 
cy it  has  a yellowish  tinge.  It  generally  extends  from  the 
thyroid  gland,  or  a little  below  it,  to  the  pericardium. 
From  its  superior  portion  two  lateral  processes  are  ex- 
tended upwards:  below,  it  is  formed  into  two  lobes,  which 
lie  on  the  pericardium. 

If  an  incision  be  made  into  its  substance,  a fluid  can  be 
pressed  out,  which  has  a whitish  color,  and  coagulates 
upon  the  addition  of  alcohol. 

Although  it  is  called  a gland , no  excretory  duct  has 
ever  been  found  connected  with  it. 

The  bloodvessels  of  this  body  are  derived  from  the  thy- 
roid branches  of  the  subclavians,from  the  internal  mamma- 
ries, and  the  vessels  of  the  pericardium  and  mediastinum. 

The  Heart , 

And  the  great  arteries  which  proceed  from  it,  have  some 
very  interesting  peculiarities  in  the  foetus. 

In  the  septum  between  the  two  auricles,  is  a foramen 
of  sufficient  size  to  permit  the  passage  of  a large  quill, 
which  inclines  to  the  oval  form,  with  its  longest  diameter 
vertical  when  the  body  is  erect.  On  the  left  side  of  the 
septum,  a valve,  formed  by  the  lining  membranes,  is  con- 
nected to  this  foramen;  and  allows  a free  passage  to  a fluid 
moving  from  the  right  auricle  to  the  left,  but  prevents  the 
passage  of  a fluid  from  the  left  to  the  right.  This  structure 


70 


The  Thorax  of  the  Fcctus. 

is  evidently  calculated  to  allow  some  of  the  blood  which 
flows  into  the  right  auricle  from  the  two  venae  cavae  to  pass 
into  the  left  auricle  of  the  heart,  instead  of  going  into  the 
right  ventricle.  As  the  contents  of  the  left  auricle  pass 
into  the  left  ventricle,  and  from  thence  into  the  aorta,  it  is 
obvious  that  the  blood,  which  passes  from  the  right  auricle 
into  the  left  through  this  foramen,  must  be  transmitted 
from  the  system  of  the  vena  cava  to  the  system  of  the 
aorta  without  going  through  the  lungs,  as  it  must  neces- 
sarily do  in  subjects  who  do  not  enjoy  the  foetal  structure. 

The  Pulmonary  Artery  and  the  Aorta 

Have  a communication  in  the  foetus,  which  is  very  ana- 
logous to  the  communication  between  the  auricles  of  the 
heart. 

From  the  pulmonary  artery,  where  it  divides  into  the 
two  great  branches,  another  large  branch  continues,  in  the 
direction  of  the  main  trunk,  until  it  joins  the  aorta;  with 
which  it  communicates  at  a small  distance  below  the  ori- 
gin of  the  left  subclavian  artery.  In  the  young  subject  that 
has  never  respired,  it  appears  as  if  the  pulmonary  artery 
was  continued  into  the  aorta,  and  sent  off  in  its  course,  a 
branch  on  each  side,  much  smaller  than  itself,  to  each  lung. 
In  subjects  that  have  lived  a few  days,  these  branches  to 
the  lungs  are  much  larger;  and  then  the  main  pulmonary 
artery  appears  to  have  divided  into  three  branches:  one  to 
each  lung,  and  one  to  the  aorta;  but  that  which  continues 
to  the  aorta  is  larger  than  either  of  the  others. 

In  the  course  of  time,  however,  this  branch  to  the  aorta 
is  contracted,  so  that  no  fluid  passes  through  it;  and  it  has 
the  appearance  of  a ligament,  in  which  state  it  remains. 

The  course  of  the  blood  from  the  right  ventricle, 
through  the  pulmonary  artery,  to  the  aorta  below  its  curve, 
is  more  direct  than  that  from  the  left  ventricle  to  the  same 
spot,  through  the  aorta  at  its  commencement.  The  column 


General  Observations. 


71 


of  blood  in  the  aorta  below  its  curve  is  evidently  propel- 
led by  the  force  of  both  ventricles:  and  this  circumstance, 
although  it  seems  to  proceed  merely  from  the  state  of  the 
fatal  lungs,  is  particularly  calculated  for  the  very  exten- 
sive circulation  which  the  foetus  carries  on,  by  means  of 
the  umbilical  arteries  and  vein  in  the  placenta. 

The  Lungs  of  the  Foetus 

Differ  greatly  from  those  of  the  adult.  They  appear 
solid,  as  if  they  were  composed  of  the  parenchymatous 
substance  which  constitutes  the  matter  of  glands,  rather 
than  the  light  spongy  substance  of  the  lungs  of  adults. 
They  differ  also  in  color  from  the  lungs  of  older  subjects, 
being  of  a dull  red. 

They  have  greater  specific  gravity  than  water;  but  if 
air  be  once  inspired,  so  much  of  it  remains  in  them  that 
they  ever  afterwards  float  in  that  fluid. 

The  nature  of  the  process  of  respiration,  and  its  effects 
upon  the  animal  economy,  particularly  upon  the  action 
of  the  heart,  appear  to  be  much  better  understood  at 
this  time  than  they  were  before  the  discovery  of  the 
composition  of  the  atmosphere,  by  Dr.  Priestley  and 
by  Mr.  Scheele.  The  publications  upon  this  subject, 
which  have  appeared  since  that  period,  viz.  1774,  are 
therefore  much  more  interesting  to  the  student  of  me- 
dicine than  those  which  preceded  them.  Two  of  these 
publications  ought  to  be  particularly  noticed  by  him: 
viz.  an  Essay,  by  Dr.  Edward  Goodwyn,  intitled  “ The 
Connexion  of  Life  with  Respiration;”  and — the  “ Phy- 
siological Researches  of  M.  Bichat  upon  Life  and 
Death.  Part  Second.”* 

* The  student  will  derive  much  information  respecting  the  publica- 
tions on  this  subject,  prior  to  1804,  from  Dr.  Bostock’s  Essay  on  Res- 
piration.— Since  the  publication  of  that  essay  several  interesting  papers 
on  respiration  have  appeared,  viz:  Two  Memoirs  by  the  late  Abbe 
Spalanzani; — “ An  Inquiry  into  the  Changes  induced  on  Atmospheric 


72 


Cases  of  Malformation. 

The  general  doctrines  respecting  the  oxygenation  or  de- 
carbonation  of  the  blood,  and  the  absolute  necessity 
that  it  should  take  place  to  a certain  degree  in  order 
to  preserve  life,  are  confirmed  by  a number  of  cases 
of  malformation  of  the  heart  or  the  great  vessels,  in 
which  the  structure  was  such  that  a considerable  por- 
tion of  venous  blood  passed  from  the  right  side  of  the 
heart  to  the  aorta,  without  going  through  the  lungs. 
In  these  different  cases,  notwithstanding  the  structure 
was  somewhat  varied,  the  symptoms  produced  were 
very  much  alike;  differing  in  the  respective  patients  in 
degree  only,  and  not  in  kind. 

The  symptoms  indicating  this  structure  are  blue  color 
of  the  face,  (such  as  generally  accompanies  suffocation) 
extending  more  or  less  over  the  whole  body,  and  par- 
ticularly apparent  under  the  nails  of  the  fingers  and 
toes;  anxiety  about  the  region  of  the  heart;  palpitation; 
laborious  respiration;  sensations  of  great  debility,  8tc.: 
all  of  which  are  greatly  aggravated  by  muscular  exer- 
tion. These  effects  have  generally  appeared  to  be  pro- 
portioned to  the  quantity  of  venous  blood  admitted  into 
the  aortic  system.! 

When  these  appearances  take  place  immediately 
after  birth,  it  is  probable  that  they  depend  entirely  up- 
on malformation  of  the  heart  or  great  vessels;  but  when 
they  commence  at  a subsequent  period,  they  are  com- 
monly the  effect  of  a diseased  alteration  in  the  lungs. 
They  sometimes  occur  near  the  termination  of  fatal 
cases  of  pneumonia  or  catarrh;  but  a different  cause, 
which  has  not  latterly  been  suspected,  appears  to  have 
produced  them  in  the  following  case  related  by  Dr. 

Air  by  the  Germination  of  Seeds,  &c.”  by  Ellis; — two  very  important 
Communications  by  Messrs.  Allen  and  Pepys  in  the  Transactions  of 
the  Royal  Society  of  London  for  1808  and  1800; — and  “Further  Inqui- 
ries into  the  Changes  induced  on  Atmospheric  Air.”  Also  by  Ellis. 

! Cases  of  this  kind  are  related  in  several  of  the  periodical  publica- 
tions on  medical  subjects.  Two  of  them  were  described  by  the  late  Dr. 


Adhesion  of  the  Lungs  to  the  Thorax.  73 

Marcet,  in  the  first  volume  of  the  Edinburgh  Medical 
and  Physical  Journal. 

The  blue  color  occurred  in  a young  woman  twenty- 
one  years  of  age,  in  whom  it  had  never  been  observed 
before.  It  came  on  during  an  affection  of  the  breast,  and 
was  attended  with  great  prostration  of  strength  and  dif- 
ficulty of  breathing;  as  well  as  cough,  oedema  of  the 
hands  and  feet,  and  several  other  symptoms.  About 
seven  weeks  after  the  commencement  of  these  symp- 
toms she  died;  when  it  was  ascertained  by  dissection, 
that  there  was  no  unnatural  communication  whatever 
between  the  cavities  of  the  heart , and  that  its  valves 
were  all  in  a perfect  and  natural  state.  The  lungs  were 
free  from  tubercles,  or  any  other  appearance  of  disease. 
Their  substance  seemed  more  compact  than  usual,  espe- 
cially the  left  lung,  although  it  did  not  sink  in  water; 
but  they  adhered  every  where  to  the  inner  surface  of  the 
thorax , to  the  diaphragm , and  to  the  pleura  covering  the 
pericardium. — This  case  is  the  more  remarkable,  be- 
cause numberless  instances  have  occurred  in  which 
very  large  portions  of  the  external  surface  of  the  lungs 
have  been  found  upon  dissection  to  adhere  to  the  inter- 
nal surface  of  the  thorax  without  the  occurrence  of 
such  symptoms  during  life. 


It  may  be  inferred,  from  a statement  published  by  M.  Du- 
puytren  in  a late  volume  of  the  Proceedings  of  the  Na- 
tional Institute  of  France,  that  the  oxygenation  or  de- 
carbonalion  of  the  blood  is  much  affected,  in  respiration, 
by  an  influence  exercised  by  the  nerves  which  are  ap- 
propriated to  the  lungs.  From  his  account  it  appears, 

William  Hunter  in  the  sixth  volume  of  Medical  Observations  and  In- 
quiries, by  a Society  of  Physicians  in  London ; one  (quoted  by  Dr.  Good- 
wyn)  is  in  the  Observationes  Anatomies  of  Sandifort;  and  another,  by 
Dr,  J.  S.  Dorsey,  has  lately  been  published  in  the  first  number  of  the 
New  England  Journal  of  Medicine  and  Surgery. 

Vol.  II.  K 


74 


Effects  of  Venous  Blood  on  the  Heart. 

that  although  the  complete  division  of  the  eighth  pair 
of  nerves  produces  death  after  some  time;  yet,  in  the 
horse  whose  nerves  are  thus  divided,  life  continues, 
and  respiration  goes  on,  from  half  an  hour  to  ten  hours; 
but  his  arterial  blood  is  in  a state  of  great  disoxygena- 
tion  or  carbonation,  during  this  time. — This  fact  is  more 
remarkable,  because  venous  blood,  contained  in  a blad- 
der exposed  to  the  open  air,  will  become  oxygenated 
or  decarbonated. 

It  is  also  asserted  in  another  Memoir,  read  to  the  Na- 
tional Institute  by  Dr.  J.  M.  Provencal,  that  animals  in 
whom  the  eighth  pair  of  nerves  has  been  divided,  do  not 
consume  so  much  oxygen,  or  produce  so  much  carbonic 
acid,  by  a considerable  degree,  as  they  did  before  the 
division  of  these  nerves;  and  that  their  temperature  is 
considerably  reduced.* 


The  fact,  that  venous  blood  occasions  death  when  it  is  ad- 
mitted into  the  left  ventricle  of  the  heart,  and  the  aorta, 
is  truly  important.  Dr.  Goodwin  explained  it  by  sug- 
gesting that  this  blood  was  not  sufficiently  stimulating 
to  produce  the  necessary  excitement  of  the  heart;  but 
on  this  occasion  one  of  his  friends  proposed  to  him  the 
following  question:  Why  does  venous  blood  affect  the 
left  side  of  the  heart  in  this  injurious  manner,  when  it 
appears  to  exert  no  noxious  effects  whatever  on  the 
right  side  of  that  organ?  His  reply  may  be  seen  in  a 
note  at  the  82d  page  of  his  Essay,  in  the  first  edition. 
Bichat  has  offered  a solution  which  completely  re- 
solves this  difficulty,  viz.  “ The  effect  of  venous  blood 
upon  the  heart  is  produced  by  the  presence  of  this  blood 
in  the  proper,  or  coronary,  arteries  of  that  organ,  and 
not  in  its  great  cavities.”  For  the  animation  of  the  heart, 
like  that  of  the  other  parts  of  the  body,  depends  upon 

* These  Memoirs  are  republished  in  the  Eclectic  Repertory  of  Phila- 
delphia for  April  and  October  1811. 


75 


Sentiments  of  Sabatier , & c. 

the  state  of  the  blood  in  the  arteries  which  penetrate  its 
texture.*  And  while  the  heart  acts,  the  blood  of  the 
coronary  arteries  will  be  the  same  with  that  of  the  left 
ventricle.  See  Bichat’s  Researches,  P.  II,  art.  6,  § 2. 

The  French  Anatomists  appear  to  entertain  some  peculiar 
opinions  respecting  the  course  of  the  blood  in  the  foetus, 
which  have  a particular  relation  to  the  subject  last  men- 
tioned. Winslow,  who  paid  great  attention  to  the  valve 
of  Eustachius  in  the  right  auricle  of  the  heart,  was  of 
opinion,  that  this  valve  was  calculated  for  some  impor- 
tant purpose  in  the  foetal  ceconomy.t  Although  his  hy- 
pothesis respecting  its  particular  use  has  not  been  re- 
tained by  his  countrymen,  many  of  them  have  adopted 
his  general  sentiment;  and  among  others  Sabatier. 
That  learned  anatomist  believed  that  this  valve,  in  the 
foetal  state,  serves  to  direct  the  blood  of  the  inferior  cava , 
after  its  arrival  in  the  right  auricle , through  the  fora- 
men ovale  into  the  left  auricle ; •while  the  blood  of  the  up- 
per cava  passes  directly  into  the  right  ventricle.  His 
opinion  seems  to  be  supported  to  a certain  degree, 

1.  By  the  direction  in  which  the  two  columns  of  blood 
enter  the  auricle  from  the  two  venae  cavae. 

2.  By  the  position  of  the  Eustachian  valve. 

3.  By  the  foramen  ovale,  when  its  valve  is  complete; 
as  the  passage  through  it,  from  the  right  to  the  left,  is 
at  that  time  oblique,  and  from  below  upwards. 

The  theory  of  Sabatier  appears  to  be  this:  The  um- 
bilical vein  brings  from  the  placenta  blood  which  has  a 
quality  essential  to  the  animation  of  the  foetus.  If  there 
were  no  particular  provision  to  the  contrary,  a large 
portion  of  this  blood,  after  passing  from  the  umbilical 
vein  by  the  inferior  cava  into  the  right  auricle  of  the 

* It  is  probable  that  the  contents  of  the  great  cavities  of  the  heart 
have  no  more  effect  upon  its  animation  than  the  contents  of  the  stomach 
and  bowels  have  upon  the  animation  of  those  organs, 
f See  Memoirs  of  the  Academy  of  Sciences  for  1717  and  1725. 


76 


Sentiments  of  Sabatier 

heart,  would  proceed  by  the  right  ventricle,  through 
the  pulmonary  artery  and  arterial  canal,  into  the  aorta, 
below  the  origins  of  the  carotid  and  subclavian  arte- 
ries; and  consequently  none  of  it  would  pass  to  the 
head  and  upper  extremities,  but  a considerable  part 
would  return  again  by  the  umbilical  arteries  to  the 
placenta,  without  circulating  through  the  body:  while 
on  the  other  hand,  the  blood  which  passed  by  the  ca- 
rotid and  subclavian  arteries  to  the  head  and  upper 
extremities,  returning  from  them  to  the  heart  by  the 
superior  cava,  might  pass  from  the  right  auricle  to 
the  left  auricle  and  ventricle  and  the  aorta,  and  so  to 
the  head  and  upper  extremities  again,  without  passing 
through  the  placenta  But  by  means  of  this  valve,  the 
blood  of  the  lower  cava,  and  of  course  of  the  umbilical 
vein,  is  directed  to  the  left  auricle  and  ventricle  and 
the  aorta,  by  which  a considerable  portion  of  it  will  ne- 
cessarily pass  to  the  head  and  upper  extremities: 

, while  the  blood  which  returns  from  these  parts  by  the 
superior  cava,  must  consequently  pass  from  the  rightau- 
ricle  into  the  right  ventricle  and  pulmonary  artery;  from 
whence  a large  portion  of  it  will  proceed  through  the 
arterial  canal  into  the  aorta  beyond  the  carotids  and  sub- 
clavians,  and  of  this  portion  a considerable  part  will  go 
to  the  placenta  by  the  umbilical  arteries.  Sabatier  com- 
pares the  course  of  the  blood  in  the  foetus  to  the  course 
of  a fluid  in  a tube  which  has  the  form  of  the  nume- 
ral character  8.* — If  this  doctrine  be  true,  the  progress 
of  the  blood  in  the  foetus  and  placenta  is  very  analogous 
to  that  of  the  double  circulation  of  the  adult;  the  cha- 
racter 8 answering  equally  well  in  the  description  of 
either  subject. 

According  to  Sabatier,  the  blood  of  the  placenta 
takes  this  peculiar  course  through  the  heart, in  orderthat 

* See  Sabatier’s  Paper  on  this  subject  in  the  Memoirs  of  the  Acade- 
demy  of  Sciences,  for  1774. 


77 


respecting  the  Foetal  Circulation. 

some  of  it  may  be  carried  to  the  head  and  upper  ex- 
tremities. But  an  additional  reason  may  be  suggested, 
which  appears  to  be  of  great  importance;  viz.  the  sup- 
plying of  the  coronary  or  proper  vessels  of  the  heart 
with  some  of  the  same  blood. 

The  heart  of  the  adult,  as  has  been  before  stated, 
cannot  act  without  its  proper  or  coronary  arteries 
are  supplied  with  arterial  blood.  The  heart  of  the  foetus 
performs  a more  extensive  circulation  than  that  of  the 
adult,  and  therefore  is  probably  in  greater  need  of  such 
blood.  But  unless  the  blood  of  the  placenta  passes  through 
the  foramen  ovale  into  the  left  auricle  and  ventricle , and 
to  to  the  aorta , it  cannot  enter  the  coronary  arteries  ivhich 
originate  at  the  commencement  of  the  aorta;  for  the 
blood  which  flows  from  the  right  side  of  the  heart 
through  the  arterial  canal,  passes  into  the  aorta  at  so 
great  a distance  from  the  orifices  of  the  coronary  arte- 
ries, that  it  certainly  cannot  enter  them. 

The  whole  of  this  doctrine  seems  to  be  supported  by 
a fact,  veryfamiliar  to  accoucheurs,  viz.  the  occurrence 
of  death  in  the  fetus  whenever  the  circulation  through 
the  umbilical  cord  is  suspended  during  fifteen  or  twenty 
minutes:  for  as  the  placenta  imparts  to  the  fetal  blood 
a quality  essential  to  life,  some  arrangement  seems  ne- 
cessary to  provide  for  the  equal  distribution  of  the 
blood  which  comes  from  this  organ,  and  especially  for 
carrying  the  requisite  proportion  of  it  to  the  substance 
of  the  heart. 

Life  has  existed  for  some  time  with  a structure  very  dif- 
ferent indeed  from  that  which  is  natural.  In  the  series 
of  elegant  engravings  relating  to  morbid  anatomy,  pub- 
lished by  Dr.  Baillie,  is  the  representation  of  a heart, 
in  which  the  venae  cavae  opened  into  the  right  auricle, 
and  the  pulmonary  veins  into  the  left  auricle,  in  the 
usual  manner;  but  the  aorta  arose  entirely  from  the 
right  ventricle,  and  the  pulmonary  artery  as  completely 


Unusual  Cases  of  Malformation. 

from  the  left. — The  canalis  arteriosus,  however,  passed 
from  the  pulmonary  artery  to  the  aorta,  and  the  fora- 
men ovale  existed.  In  this  case  it  is  evident  that  the 
pulmonary  artery  must  have  carried  back  to  the  lungs 
the  arterial  blood  which  came  from  them  by  the  pul- 
monary veins,  with  a small  quantity  of  venous  blood 
that  passed  into  the  left  auricle  through  the  foramen 
ovale;  and  that  the  aorta  must  have  returned,  to  the 
body,  the  venous  blood  which  just  before  had  been 
brought  from  it  by  the  venae  cavae,  with  a small  addi- 
tion of  arterial  blood  that  passed  through  the  ductus 
arteriosus.  Yet,  with  this  structure,  the  child  lived  two 
months  after  its  birth. 

A case,  which  had  a strong  resemblance  to  the  forego- 
ing, occurred  lately  in  Philadelphia,  and  was  examined 
by  the  author  of  this  work.  The  venae  cavae  terminated 
regularly  in  the  right  auricle,  and  the  pulmonary  veins 
in  the  same  regular  manner  in  the  left;  but  the  pulmo- 
nary artery  arose  from  the  left  ventricle,  and  the  aorta 
from  the  right.  There  was  no  communication  between  these 
vessels  by  a canalis  arteriosus;  but  a large  opening  exist- 
ed in  the  septum  between  the  auricles. 

It  is  very  evident,  that  in  this  case  also  the  pulmonary- 
artery  must  have  returned  to  the  lungs  the  arterial  Hood 
as  it  came  from  them,  and  the  aorta  must  have  carried 
back  to  the  general  system  the  venous  blood  brought  to 
the  heart  by  the  cavae;  excepting  only  those  portions  of 
the  artei’ial  and  venous  blood  which  must  have  flowed 
reciprocally  from  one  auricle  into  the  other,  and  thus 
changed  their  respective  situations. 

The  subject  was  about  two  years  and  a half  old.  The 
heart  was  nearly  double  the  natural  size,  and  the  fora- 
men, or  opening  in  the  septum  between  the  auricles, 
was  eight  or  nine  lines  in  diameter.  The  pulmonary  ar- 
tery was  larger  in  proportion  than  the  aorta  or  the  heart. 

With  this  organization  the  child  lived  to  the  age 
above  specified.  His  countenance  was  generally  rather 


Foramen  Ovale. 


79 


livid;  and  this  color  was  always  much  increased  by 
the  least  irregularity  of  respiration.  His  nails  were 
always  livid.  He  sometimes  appeared  placid,  but  more 
frequently  in  distress.  He  never  walked,  and  seldom,  if 
ever,  stood  on  his  feet.  When  sitting  on  the  floor,  he 
would  sometimes  push  himself  about  the  room;  but 
this  muscular  exertion  always  greatly  affected  his  res- 
piration. He  attained  the  size  common  to  children  of 
his  age,  and  had  generally  a great  appetite.  For  some 
weeks  before  death  his  legs  and  feet  were  swelled. 

It  is  probable  that  the  protraction  of  life  depended 
upon  the  mixture  of  the  blood  in  the  two  auricles;  and 
that  they  really  were  to  be  considered  as  one  cavity,  in 
this  case. 

There  seems  reason  to  believe,  that  in  adults  of  the  com- 
mon structure,  there  is  no  passage  of  blood  from  one 
auricle  to  the  other,  when  the  foramen  ovale  has  re- 
mained open;  because  in  several  persons  in  whom 
it  was  found  by  dissection  to  have  remained  open, 
there  were  no  appearances  during  life  that  indicated 
the  presence  of  disoxygenated  blood  in  the  aortic  sys- 
tem. It  is  probable,  that  the  small  size  of  the  foramen 
ovale,  the  valvular  structure  which  generally  exists 
there,  and  the  complete  occupation  of  the  left  auricle  by 
the  blood  flowing  from  the  pulmonary  veins,  prevent 
the  passage  of  blood  from  the  right  auricle  to  the  left,  in 
such  persons;  whereas,  in  the  case  in  question,  the  open- 
ing between  the  auricles  was  very  large  indeed,  and 
there  was  no  appearance  of  a valve  about  it. 

Although  it  be  admitted,  that  in  adults  with  the  fora- 
men ovale  pervious,  there  is  no  transmission  of  blood 
from  the  right  to  the  left  auricle;  there  is  every  reason 
to  believe  that  this  transmission  goes  on  steadily  in  the 
foetus.  To  the  arguments,  derived  from  the  structure 
and  the  nature  of  the  case,  it  may  be  added,  that  the 
pulmonary  veins,  in  the  foetal  state,  carry  to  the  left 


80  Legallois  on  the  Source  of  the  Motion  of  the  Heart. 

auricle  a quantity  of  blood,  not  sufficient  to  fill  it;  while 
the  venae  cavse  carry  to  the  right  auricle  not  only  the 
whole  blood  of  the  body,  but  of  the  umbilical  cord  and 
placenta:  some  of  which  must  flow  into  the  unfilled  left 
auricle,  when  the  right  auricle  becomes  fully  distended. 

The  question  how  far  the  functions  of  the  heart  and  lungs 
are  dependent  upon  the  brain  is  very  important,  and 
has  often  been  agitated  with  great  zeal.  In  favor  of  the 
opinion  that  the  motions  of  the  heart  are  independent 
of  the  brain,  may  be  stated  the  numerous  cases  in  which 
the  brain  has  been  deficient  in  children,  who  have  not- 
withstanding lived  the  full  period  of  utero  gestation, 
and  even  a short  time  after  birth,  and  have  arrived  at 
their  full  size,  with  every  appearance  of  perfect  vigor 
and  action  in  the  heart.  In  support  of  the  doctrine,  that 
the  action  of  the  heart  is  immediately  dependent  upon 
the  brain,  it  may  be  observed,  that  no  organ  of  the  body 
appears  to  be  so  much  influenced  by  passions  and  other 
mental  affections  as  the  heart.  These  contradictory  facts 
have  occasioned  this  question  to  be  considered  as  un- 
decided, if  not  incapable  of  solution;  although  Cruik- 
shank  and  Bichat*  have  stated  circumstances  very  fa- 
vorable to  the  opinion  that  the  motions  of  the  heart  are 
independent  of  the  brain. 

This  question  seems  now  to  be  settled  by  the  ex- 
periments of  Dr.  Legallois,  a physician  of  Paris,  which 
prove,  that  in  animals  who  have  suffered  decafiita- 
tion , the  action  of  the  heart  does  not  cease  as  an  im- 
mediate consequence  of  the  removal  of  the  head;  but 

* See  Cruikshank’s  Experiments  on  the  Nerves  and  Spinal  Marrow 
of  living  animals;  London  Philosophical  Transactions  for  1795.  The 
eighth  experiment  has  a particular  relation  to  this  subject. 

Bichat’s  Researches,  part  2,  article  9. 

The  Abbe  Fontana  has  considered  this  subject  in  his  Treatise  on 
the  Venom  of  the  Viper,  vol.  ii.  page  194.  English  translation;  and  also 
in  spnie  of  his  other  works. 


Humboldt  and  Others  on  Legallois ’ Paper.  81 

its  cessation  is  an  indirect  effect , induced  by  the  sus- 
pension of  respiration.  That  respiration  is  immediately 
affected  by  decapitation,  and  depends  upon  the  influ- 
ence of  the  brain  transmitted  through  the  eighth  pair 
of  nerves.  That  the  action  of  the  heart  will  continue  a 
longtime  after  decapitation,  if  inflation  of  the  lungs,  or 
artificial  respiration,  be  performed;  but,  on  the  contra- 
ry, if  the  spinal  marrow  be  destroyed,  the  action  of  the 
heart  ceases  irrecoverably. 

The  inference  from  these  experiments  seems  very 
conclusive,  that  the  Spinal  Marrow , and  not  the  brain,  is 
the  source  of  the  motions  of  the  heart. 

It  appears  also  by  some  of  the  experiments,  that  the 
power  of  motion  in  the  trunk  of  the  body  is  derived 
from  the  spinal  marrow;  and  that  when  this  organ  is 
partially  destroyed,  the  parts  which  receive  nerves  from 
the  destroyed  portion  soon  cease  to  live.  By  particular 
management  of  the  spinal  marrow,  one  part  of  the  body 
can  be  preserved  alive  for  some  time  after  the  other 
parts  are  dead. 

These  experiments  of  Dr.  Legallois  commenced  in  1806 
or  1807,  and  were  communicated  to  the  Imperial  Insti- 
tute of  France  in  181 1.  The  committee  of  that  body  to 
whom  they  were  referred,  viz.  Messrs.  Humboldt, 
Halle  and  Percy,  reported  that  the  experiments  had 
been  repeated  before  them,  at  three  different  meetings 
of  several  hours  each;  and  that  to  allow  themselves  suf- 
ficient time  for  reflection,  they  suffered  an  interval  of  a 
week  to  take  place  between  the  meetings.  The  com- 
mittee believe  these  experiments  to  have  proved, 

1st.  That  the  principle  uponwhich  all  the  movements 
of  inspiration  depend,  has  its  seat  about  that  part  of  the 
medulla  oblongata  from  which  the  nerves  of  the  eighth 
pair  arise. 

VOL.  II. 


L 


82  Brodie  on  the  Source  of  the  Motion  of  the  Heart. 

2d.  That  the  principle  which  animates  each  part  of  the 
trunk  of  the  body  is  seated  in  that  portion  of  the  spinal 
marrow  from  which  the  nerves  of  the  part  arise. 

3d.  That  the  source  of  the  life  and  strength  of  the 
heart  is  also  in  the  spinal  marrow;  not  in  any  distinct 
portion,  but  in  the  whole  of  it. 

4th.  That  the  great  sympathetic  nerve  is  to  be  consi- 
dered as  originating  in  the  spinal  marrow,  and  that  the 
particular  character  of  this  nerve  is  to  place  each  of 
the  parts  to  which  it  is  distributed  under  the  immedi- 
ate influence  of  the  whole  nervous  power. 

The  interesting  memoir  of  Dr.  Legallois  is  confirmed  to 
a certain  degree  by  a communication  of  B.  C.  Brodie 
to  the  Royal  Society  of  London  in  1810,  in  which  are 
detailed  many  very  interesting  experiments  which  in- 
duced the  author  to  conclude, — 

That  the  influence  of  the  brain  is  not  directly  neces- 
sary to  the  action  of  the  heart;  and 

That  when  the  brain  is  injured  or  removed,  the  ac- 
tion of  the  heart  ceases,  only  because  respiration  is  un- 
der its  influence;  and  if  under  these  circumstances  res- 
piration is  artificially  produced,  the  circulation  will  still 
continue. 

These  various  experiments  apply  particularly  to  the  cases 
in  which  the  brain  is  deficient.  The  effects  of  mental 
agitations  on  the  heart  are  likewise  reconcilable  to  the 
theory  which  arises  out  of  them.  But  they  throw  no 
light  on  the  question  why  the  motions  of  the  heart  are 
so  perfectly  free  from  the  influence  of  the  will:  ancl 
although  they  seem  to  prove  inconteslibly  that  the  mo- 
tion of  the  heart  is  independent  of  the  brain,  it  ought 
to  be  remembered  that  in  certain  diseased  states  of  the 
brain,  where  that  organ  appears  to  be  compressed,  the 
action  of  the  heart  is  often  very  irregular,  and  its  con- 
tractions less  frequent  than  usual. 


SYSTEM  OF  ANATOMY. 


PART  VIII. 


OF  THE  ABDOMEN. 

The  lowermost  of  the  two  great  cavities  of  the  trunk 
of  the  body  is  called  Abdomen.  The  pelvis  may  be  consi- 
dered as  a chamber  of  this  cavity,  although  its  structure  is 
very  different. 

CHAPTER  I. 

A GENERAL  VIEW  OF  THE  ABDOMEN  AND  PELVIS  AND  THEIR 
CONTENTS,  WITH  AN  ACCOUNT  OF  THE  PERITONEUM. 

SECTION  I. 

Of  the  Abdomen . 

THIS  great  cavity  occupies  more  than  half  of  the  space 
inclosed  by  the  ribs,  and  all  the  interior  of  the  trunk  of  the 
body  below  the  thorax. 

It  is  formed  by  the  diaphragm,  supported  by  the  lower 
ribs;  by  a portion  of  the  spine;  by  the  various  muscles 
which  occur  between  the  lower  margin  of  the  thorax  and 
the  upper  margin  of  the  ossa  innominata;  and  by  the  ossa 


84  Construction  of  the  Abdomen . 

innominata,  which  contribute,  for  the  purpose,  the  costae  of 
the  ossa  ilea,  as  well  as  the  pelvis. 

The  general  figure  of  this  cavity  partakes  of  the  figure 
of  the  lower  part  of  the  trunk  of  the  body;  with  these  ex- 
ceptions, that  the  diaphragm  makes  it  arched  or  vaulted 
above,  that  the  spine  and  psoas  muscles,  &c.  are  rather 
prominent  on  the  posterior  surface,  and  that  the  lower 
part  corresponds  with  the  costae  of  the  ossa  ilea  and  with 
the  pelvis. 

To  acquire  a precise  idea  of  this  cavity,  it  is  necessary 
first  to  study  the  bones  concerned  in  its  structure,  in  their 
natural  situation  in  the  skeleton;  and  then  the  muscles, 
which  form  so  large  a part  of  it. 

The  arrangement  of  the  tendons  of  some  of  these  mus- 
cles, with  a view  to  complete  the  cavity,  is  particularly 
interesting;  as  that  of  the  external  oblique  when  it  forms 
the  crural  arch.*  The  ligaments  of  the  pelvis  and  the  le- 
vatores  ani  muscles,  as  they  also  contribute  to  the  forma- 
tion of  the  cavity,  and  have  an  influence  upon  its  figure, 
should  likewise  be  attended  to. 

In  the  walls  of  the  -cavity,  thus  constructed,  there  are 
many  foramina  by  which  the  viscera  and  other  contained 
parts  communicate  externally;  but  few  of  them  pass  di- 
rectly into  the  cavity;  for  like  the  thorax,  there  are  no  va- 
cuities in  it  exterior  to  the  contained  organs. 

Three  of  these  foramina  are  in  the  diaphragm.  One  for 
the  transmission  of  the  aorta,  another  for  the  vena  cava, 
and  a third  for  the  oesophagus.  Below,  there  is  an  aperture 
at  each  of  the  crural  arches,  for  the  transmission  of  the 
great  femoral  vessels;  in  each  of  the  ligamentous  mem- 
branes, which  close  the  foramen  thyroideum,  for  the  obtu- 


See  the  account  of  this  tendon,  vol.  i.  page  197. 


Construction  of  the  Abdomen.  85 

rator  vessels  and  nerve ; and  at  the  sacro  sciatic  notches, 
for  nerves  and  bloodvessels. 

There  are  also  two  apertures  at  the  bottom  of  the  pel- 
vis, for  the  orifice  of  the  rectum  and  of  the  urethra.  In  the 
tendons  of  the  external  oblique  muscles  are  two  orifices, 
covered  by  the  integuments,  for  the  spermatic  cords;  and, 
in  the  foetal  state,  one  for  the  umbilical  cord. 

The  apertures  in  the  tendons,  and  under  their  edges, 
for  the  transmission  of  the  spermatic  cords,  and  the  blood- 
vessels, &c.  are  not  to  be  considered  as  simple  perfora- 
tions made  abruptly;  but  the  edges  of  these  foramina  are 
formed  by  tendinous  membranes  turned  inwards  and  con- 
tinued so  as  to  compose  a cylindrical  tube,  which  becomes 
gradually  so  thin  that  it  cannot  be  readily  distinguished 
from  the  cellular  membrane  with  which  it  is  connected.* 
The  bloodvessels,  &c.  pass  along  this  tube  before  they  go 
through  the  apertures. 

It  is  evident  from  the  construction  of  this  cavity  that 
it  is  essentially  different  from  the  thorax.  It  has  no  power 
of  spontaneous  dilatation  whatever:  it  yields  passively  to 
the  distention  of  the  stomach  and  intestines,  during  deglu- 
tition,  and  when  air  is  extricated  from  the  aliment,  &c.;  but 
it  is  particularly  calculated  for  compressing  its  contents  by 
the  contraction  of  the  muscles  which  compose  it.  The 
diminution  of  its  capacity,  which  is  thus  effected,  not  only 
takes  place  to  a great  degree,  but  occasionally  with  great 
force.  The  diaphragm  and  the  abdominal  muscles  may  be 
considered  in  some  measure  as  antagonists  of  each  other. 
When  the  diaphragm  descends,  if  the  abdominal  muscles 
are  passive,  they  are  distended  by  the  contents  of  the  ab- 

* The  student  of  anatomy,  when  engaged  with  this  subject,  will  be 
gratified  by  the  examination  of  Mr.  Astley  Cooper’s  plates  relating  to 
hernise. 


86 


Contents  of  the  Abdomen . 

domen,  which  are  forcibly  pressed  from  above;  but  if  the 
abdominal  muscles  act  at  the  same  time,  an  effort  to  dimi- 
nish the  cavity  in  every  direction  takes  place,  and  the  con- 
tained parts  are  compressed  with  more  or  less  force  ac- 
cording to  the  exertion  made.  This  will  be  very  evident 
upon  examining  the  situation  of  the  diaphragm  and  of  the 
abdominal  muscles.  When  their  force  is  considered  it  will 
also  be  very  obvious  that  the  various  outlets  of  the  cavity 
are  constructed  most  advantageously;  otherwise  hernia  or 
protrusion  of  its  contents  would  be  a daily  occurrence. 

The  abdomen  contains,  1st.  The  Stomach  and  the  whole 
Intestinal  Tube , consisting  of  the  small  and  the  great  in- 
testines. 

2d.  The  Assisting-  Chylopoietic  Viscera , — the  Liver,  the 
Pancreas  and  the  Spleen. 

3d.  The  Urinary  Organs,— ~ the  Kidneys,  the  Ureters, 
and  the  Bladder.  To  which  should  be  added  the  Glandu- 
lae  Renales. 

4th.  The  Organs  of  Generation  in  part:  those  of  the 
female  sex  being  almost  wholly  included  in  the  pelvis; 
and  those  of  the  male  being  situated  partly  within  and 
partly  without  it. 

5th.  The  Peritoneum  and  its  various  processes.  The 
Mesentery,  Omentum,  &c. 

6th.  A portion  of  the  Aorta , and  almost  the  whole  of  the 
Inferior  Cava , and  their  great  ramifications;  with  such  of 
their  branches  as  are  appropriated  to  the  Viscera  of  the 
Abdomen  and  Pelvis. 

7th.  Those  portions  of  the  Par  Vagum  and  Intercostal 
Nerves  which  are  appropriated  to  the  cavity;  and  portions 
of  some  of  the  nerves  destined  to  the  lower  extremities. 

8th.  The  lower  part  of  the  Thoracic  Duct , or  the  Great 
Trunk  of  the  Absorbent  System,  with  the  large  branches 


87 


Regions  of  the  Abdomen. 

that  compose  it,  and  the  glands  connected  with  them;  and 
also  those  absorbent  vessels  called  Lacteals , and  their 
glands. 

As  the  cavity  of  the  abdomen  has  no  natural  divisions, 
anatomists  have  divided  it  by  imaginary  lines  into  various 
regions,  with  a view  to  precision  in  their  accounts  of  the 
situation  of  the  different  contained  parts.  Thus, 

They  have,  very  generally,  agreed  to  apply  two  trans- 
verse lines  to  form  three  great  divisions;  viz.  the  Upper , 
Middle  and  Lower:  and  they  have  also  agreed  that  each  of 
these  divisions  shall  be  subdivided  into  three  regions. 

The  three  regions  of  the  uppermost  division  are  defined 
with  some  precision.  Those  on  each  side,  which  are  called 
the  Right  and  Left  Hypochondriac  regions , occupy  the  spa- 
ces immediately  within  the  lower  ribs  and  their  cartilages; 
while  the  middle  space,  included  within  the  margins  of 
these  cartilages,  and  a line  drawn  from  the  lower  edge  of 
the  thorax  on  one  side  to  that  on  the  other,  is  denominated 
the  Epigastric  region. 

The  boundaries  of  the  regions  below  are  less  precisely 
defined. 

Many  anatomists  have  fixed  the  two  transverse  lines 
above  mentioned  at  an  arbitrary  distance  above  and  below 
the  umbilicus:  some  choosing  for  this  purpose  two  inches, 
and  others  a hand’s  breadth.  As  these  distances  will  occu- 
py different  proportions  of  the  cavity  in  persons  of  differ- 
ent stature,  other  anatomists,  with  a view  to  avoid  this 
inconvenience,  have  proposed  to  connect  these  lines  with 
certain  fixed  points  of  the  skeleton. 

It  is  of  importance  that  the  boundaries  of  these  regions 
should  be  fixed,  and  therefore  the  proposition  of  Sabatier 
may  be  adopted;  viz.  To  draw  the  upper  transverse  line 
from  the  most  inferior  part  of  the  lower  margin  of  the 
thorax,  on  one  side,  to  the  corresponding  part  on  the  oppo- 


88  Situation  of  the  Viscera , &?c.  in  the 

site  side;  and  the  lower  transverse  line  from  the  upper- 
most part  of  the  spine  of  one  ileum  to  the  same  part  of  the 
other.  These  lines  will  mark  the  three  great  divisions.  If 
then  two  parallel  lines  are  drawn  directly  upwards,  one 
from  each  of  the  superior  anterior  spinous  processes  of  the 
ileum  until  it  touches  the  lower  margin  of  the  thorax, 
they  will  divide  each  of  the  two  lower  divisions  of  the 
abdomen  into  three  regions.  The  center  of  the  middle 
division  is  the  umbilical,  and  on  each  side  of  it  is  the  right 
and  left  lumbar  region.  The  middle  of  the  lower  division 
is  the  hypogastric;  and  on  each  side  of  it  the  right  and  left 
iliac  region. 

It  is  true,  that  the  three  middle  regions  of  the  abdomen 
will  be  made  very  small  by  the  vicinity  of  the  transverse 
lines  to  each  other;  but  the  advantages  derived  from  a 
principle  which  is  similar  in  its  application  to  all  subjects 
fully  compensates  this  inconvenience. 

There  are  therefore  nine  of  these  regions:  viz.  The 
Epigastric  and  the  two  Hypochondriac:  the  Umbilical, 
and  the  two  Lumbar:  the  Hypogastric,  and  the  two  Iliac 
regions.*  And  it  should  be  added,  that  the  space  imme- 
diately around  the  end  of  the  sternum  is  sometimes  cal- 
led the  Scrobiculus  Cordis;  and  the  space  immediately 
within  the  os  pubis,  the  llegio  Pubis. 

These  different  regions  are  generally  occupied  in  the 
following  manner.  The  liver  fills  nearly  the  whole  of  the 
right  hypochondriac  region,  and  extends  through  the  up- 
per part  of  the  epigastric  region  into  the  left  hypochon- 
driac. The  stomach  occupies  the  principal  part  of  the  epi- 

* It  is  to  be  observed  tliat  the  lateral  regions  of  the  middle  and 
lower  divisions  of  the  abdomen  are  named  differently  by  different 
writers. 


89 


Cavity  of  the  Abdomen. 

gastric  region,  and  a considerable  portion  of  the  left  hy- 
pochondriac. The  spleen  is  also  situated  in  the  left  hypo- 
chondriac region.  That  portion  of  the  intestinal  tube, 
which  is  composed  of  the  small  intestines,  i$  generally 
found  in  the  umbilical,  the  hypogastric,  and  the  iliac  re- 
gions; and  when  the  bladder  is  empty,  in  the  pelvis.  But 
the  duodenum,  or  first  of  the  small  intestines,  which  pro- 
ceeds immediately  from  the  stomach,  is  situated  in  the 
epigastric  and  umbilical  regions.  The  great  intestine 
commences  in  or  near  the  right  iliac  region,  and  ascends 
through  the  right  lumbar  to  the  right  hypochondriac  re- 
gion. It  then  crosses  the  abdomen,  passing  through  the 
lower  part  of  the  epigastric,  or  upper  part  of  the  umbilical 
to  the  left  lumbar  region;  from  this  it  continues  into  the 
left  iliac  region,  and  curves  in  such  manner  that  it  finally 
arrives  at  the  middle  of  the  upper  part  of  the  os  sacrum, 
when  it  descends  into  the  pelvis,  and,  partaking  of  the 
curvature  of  the  last  mentioned  bone,  continues  to  the 
termination  of  the  os  coccygis. 

In  the  back  part  of  the  epigastric  region,  and  very  low 
down  in  it,  is  situated  the  pancreas.  The  kidneys  lie  in 
the  most  posterior  parts  of  the  lumbar  regions,  and  from 
each  of  them  is  continued  a tube  or  duct,  called  Ureter , 
that  passes  into  the  pelvis  to  convey  the  urine  to  the  blad- 
der. This  viscus,  in  males,  is  in  contact  with  the  last  por- 
tion of  the  great  intestine  'called  the  Rectum , and  with  it 
occupies  almost  all  of  the  cavity  of  the  pelvis;  while  in  fe- 
males, the  uterus  and  its  appendages  are  situated  between 
this  intestine  and  the  bladder. 

In  the  posterior  part  of  the  abdomen,  in  contact  with 
the  spine,  is  the  aorta.  This  great  bloodvessel  passes  from 
the  thorax  between  the  crura  of  the  diaphragm,  and  con- 
tinues down  the  spine  until  it  approaches  towards  the  pel- 
Vox..  II.  M 


90  Great  Bloodvessels  in  the  Abdomen . 

vis,  when  it  divides  into  two  great  branches  called  the 
Iliac  Arteries.  Each  of  these  great  branches  divides  again, 
on  the  side  of  the  pelvis,  into  two;  viz.  the  External  Iliac , 
which  passes  under  the  crural  arch  to  the  thigh,  and  the 
Internal  Iliac , or  Hypogastric , which  descends  into  the 
cavity  of  the  pelvis. 

Soon  after  the  arrival  of  the  aorta  in  the  abdomen  it 
gives  off  two  large  branches.  The  first,  which  is  called  the 
Cceliac , is  distributed  to  the  liver,  the  stomach,  and  the 
spleen:  the  second,  called  the  Superior  Mesenteric , is 
spent  upon  the  intestines.  Eower  down,  in  the  abdomen, 
it  also  sends  off  a small  branch  for  the  intestines,  called 
the  Inferior  Mesenteric.  Besides  these  vessels  for  the 
chylopoietic  viscera,  the  aorta  sends  off  a large  branch, 
called  Emulgent , to  each  kidney. 

The  inferior,  or  ascending  vena  cava,  is  situated  on  the 
right  of  the  aorta,  in  front  of  the  spine.  It  is  formed  below 
by  the  union  of  the  iliac  veins,  and  in  its  progress  upwards 
it  receives  the  emulgent  veins,  which  correspond  to  the 
arteries  of  the  kidneys;  but  it  receives  in  its  course  no 
veins  which  correspond  directly  with  the  cceliac  and  me- 
senteric arteries.  The  smaller  veins,  that  answer  to  the 
branches  of  these  arteries,  unite  and  form  one  large  vein, 
which  goes  to  the  liver,  and  is  called  (from  the  part  of  that 
viscus  at  which  it  enters)  Vena  Portarum.  From  the  liver 
three  large  veins  pass  into  the  vena  cava,  and  deposit  there 
the  blood  of  the  vena  portarum,  after  it  has  furnished  ma- 
terials for  the  secretion  of  bile.  The  vena  cava,  in  its  pas- 
sage upwards,  is  in  close  contact  with  the  posterior  thick 
edge  of  the  liver:  it  often  passes  along  a deep  groove  in 
this  edge,  and  sometimes  it  is  completely  surrounded  by 
the  liver  in  its  course.  The  veins  of  the  liver  enter  the 
vena  cava  at  this  place,  and  of  course  they  are  not  to  be  seen 


The  Peritoneum. 


91 


without  dissection.  Immediately  after  leaving  the  liver  the 
vena  cava  passes  through  an  aperture  in  the  tendinous 
center  of  the  diaphragm  to  unite  itself  to  the  right  auri- 
cle of  the  heart. 


SECTION  II. 

Of  the  Peritoneum. 

THE  abdomen,  thus  constructed  and  occupied,  is  lined 
by  a thin  firm  membrane  called  Peritoneum , which  is  ex- 
tremely smooth  on  its  internal  surface,  and  is  intimately 
connected  with  the  cellular  substance  exterior  to  it.  This 
membrane  adheres  closely  to  the  anterior,  lateral,  and  su- 
perior portions  of  the  surface  of  the  abdomen;  and  is  ex- 
tended from  the  posterior  surface  so  as  to  cover,  more  or 
less  completely,  the  viscera  of  the  cavity.  Those  viscera 
which  are  in  close  contact  with  the  posterior  surface  of 
the  abdomen,  as  some  portions  of  the  large  intestine,  are 
covered  only  on  their  anterior  surfaces,  and  are  fixed  in 
their  precise  situations  by  the  peritoneum;  which  extends 
from  them  to  the  contiguous  surface  of  the  cavity,  and 
adheres  where  it  is  in  contact,  so  as  to  produce  this  effect. 

Other  viscera,  which  are  not  in  close  contact,  but  mova- 
ble to  a distance  from  the  posterior  surface  of  the  abdo- 
men, are  covered  by  this  membrane,  which  is  extended  to 
them  from  the  surface;  and  this  extended  portion  forms 
an  important  part  of  the  connexion  between  the  viscus  and 
the  cavity  in  which  it  lies.  This  connecting  part  is  called 
Mesentery, when  it  thus  passes  to  the  small  intestines;  Me- 
socolon, when  it  goes  to  the  colon,  one  of  the  larger  intes- 
tines; and  Ligament , when  it  passes  to  some  of  the  other 
viscera. 


92 


The  Peritoneum. 


The  peritoneum  is  a complete  but  empty  sac,  which  is 
fixed  iu  the  abdomen  anterior  to  the  viscera.  The  anterior 
portion  of  this  sac  forms  the  lining  to  the  anterior  and 
lateral  parts  of  the  surface  of  the  abdomen;  the  posterior 
portion  covers  the  viscera,  and  forms  the  mesentery,  me- 
socolon, and  ligaments  above  described. 

It  necessarily  follows  that  the  mesentery  and  the  other 
similar  processes  are  mere  plaits  or  folds  of  the  sac,  which 
invests  the  viscera;  and  that  they  must  consist  of  two 
laminae:  and  as  the  bloodvessels,  nerves,  and  absorbents, 
are  al)  posterior  to  the  peritoneum,  they  naturally  pass  be- 
tween these  laminae  of  the  mesentery. 

Some  of  the  viscera  are  much  more  completely  invested 
with  the  peritoneum  than  others.  The  stomach,  liver,  and 
spleen,  are  almost  completely  surrounded  by  it;  and  it  is 
said  to  form  a coat  for  each  of  these  viscera.  That  portion 
of  the  smaller  intestinal  tube,  which  is  called  jejunum 
and  ileum,  and  the  transverse  portion  of  the  large  intes- 
tine, called  the  arch  of  the  colon , are  invested  by  it  in  the 
same  way.  But  a considerable  portion  of  the  duodenum 
and  the  pancreas  is  behind  it.  The  lateral  portions  of  the 
colon  are  in  close  contact  with  the  posterior  surface  of  the 
abdomen,  and  the  peritoneum  only  covers  that  portion  of 
their  surfaces  which  looks  anteriorly  towards  the  cavity  of 
the  abdomen, and  is  not  in  contactwith  its  posterior  surface. 

The  urinary  organs  are  not  much  connected  with  the 
peritoneum.  The  kidneys  appear  exterior  to  it,  and  be- 
hind it:  the  bladder  of  urine  is  below  it,  and  has  but  a 
partial  covering  from  it,  on  its  upper  portion. 

The  peritoneum,  which  covers  the  stomach,  is  extended 
from  the  great  curvature  of  that  organ  so  as  to  form  a 
large  membrane,  which  descends  like  an  apron  before  the 
intestines.  This  process  of  peritoneum  is  composed  of 


The  Peritoneum. 


93 


two  lamina,  so  thin  and  delicate  as  to  resemble  cellular 
membrane,  which,  after  extending  downwards  to  the  lower 
part  of  the  abdomen,  are  turned  backwards  and  upwards, 
and  proceed  in  that  direction  until  they  arrive  at  the  co- 
lon, which  they  inclose,  and  then  continue  to  the  back  of 
the  abdomen,  forming  the  mesocolon.  The  part  of  this 
process  which  is  between  the  stomach  and  the  colon,  is 
called  Epiploon , or  Omentum. 

This  extension  of  a membrane,  from  the  surface  of  a 
cavity  which  it  lines  to  the  external  surface  of  a viscus  in 
that  cavity,  is  called,  by  some  anatomists,  “ reflection;” 
and  the  technical  term  rejected  membrane  is  therefore  ap- 
plied to  a membrane  distributed  like  the  peritoneum. 

It  must  be  evident  that  this  distribution  of  the  perito- 
neum is  very  complex,  and  that  it  is  not  easy  to  form  an 
accurate  conception  of  it  from  description,  but  it  can  be 
readily  understood  by  demonstration;  therefore  no  fur- 
ther account  of  its  arrangement  will  now  be  attempted, 
but  each  of  its  processes  will  be  considered  with  the  or- 
gans to  which  they  are  particularly  subservient. 

That  portion  of  the  peritoneum  which  lines  the  abdo- 
men and  covers  the  viscera  is  thin  and  delicate,  but  very 
firm.  It  yields  to  distention,  as  in  pregnancy,  ascites,  See.; 
and  again  recovers  its  dimensions.  It  was  formerly  thought 
to  be  composed  of  two  lamina,  but  this  cannot  be  proved. 
The  internal  surface  of  this  membrane  is  very  smooth, 
and  highly  polished;  and  from  it  exudes  a liquor  which 
is  well  calculated  for  lubrication,  and  barely  sufficient  to 
keep  the  surface  moist  during  health;  but  sometimes  it  is 
very  abundant,  and  occasions  the  aforesaid  disease-ascites. 
This  fluid  appears  to  exude  from  the  surface  of  the  peri- 
toneum when  it  is  compressed  in  a living  animal,  or  in 
one  recently  dead.  It  is  probably  effused  from  the  extre- 


94 


The  Peritoneum. 


mities  of  arteries,  for  an  effusion  takes  place  when  water 
is  injected  into  these  vessels. 

The  peritoneum  abounds  with  absorbent  vessels,  and 
therefore  possesses  the  power  of  absorption  to  a great  de- 
gree. This  power  may  be  inferred,  not  only  from  the  spon- 
taneous removal  of  the  fluid  of  ascites,  but  if  milk  and 
water  be  introduced  into  the  abdomen  of  a living  animal, 
through  a puncture,  it  will  also  disappear. 

The  bloodvessels  of  the  peritoneum  are  derived  from 
those  which  supply  the  neighboring  parts.  Nerves  have 
not  yet  been  traced  into  it,  and  it  has  little  or  no  sensi- 
bility. 

This  membrane  supports  the  viscera  of  the  abdomen  in 
their  proper  situations;  and  also  forms  a surface  for  them, 
and  for  the  cavity  which  contains  them,  so  smooth  and  lu- 
bricated, that  no  injury  can  arise  from  their  friction. 

The  cellular  substance,  by  which  the  peritoneum  is 
connected  to  the  contiguous  parts,  is  very  different  in  dif- 
ferent places.  It  is  very  short  indeed  between  this  mem- 
brane and  the  stomach  and  intestines,  and  also  between  it 
and  the  tendinous  center  of  the  diaphragm.  Between 
the  peritoneum  and  the  muscles  generally,  it  is  much 
longer.  When  it  covers  the  kidneys  and  the  psoas  mus- 
cles it  is  very  lax  and  yielding.  About  the  kidneys  a large 
quantity  of  adeps  very  commonly  collects  in  it.  On  the 
psoas  muscle  it  yields  w ith  but  little  resistance  to  the  pas- 
sage of  pus,  or  any  other  effused  fluid,  as  in  the  case  of 
the  psoas  abscess. 


95 


CHAPTER  II. 

OF  THE  (ESOPHAGUS,  THE  STOMACH,  AND  THE  INTESTINES, 

SECTION  I. 

Of  the  (Esophagus. 

THE  CEsophagus  is  a muscular  tube  which  passes  from 
the  pharynx  to  the  stomach,  and  is  so  intimately  connected 
with  the  stomach,  that  it  will  be  advantageous  to  the  stu- 
dent to  attend  to  its  structure  immediately  before  he  en- 
gages in  the  examination  of  that  important  organ. 

The  pharynx  has  been  lately  described*  as  composed  of 
a varied  stratum  of  muscular  fibres,  lined  by  a membrane 
which  is  continued  from  the  internal  surface  of  the  nose 
and  mouth.  From  the  pharynx  the  oesophagus  passes 
downwards  between  the  trachea  and  the  vertebrae.  After 
the  bifurcation  of  the*trachea,  it  proceeds  in  contact  with 
the  spine,  between  the  laminae  of  the  mediastinum,  to  the 
diaphragm,  which  it  passes  through,  and  then  terminates 
in  the  stomach. 

The  oesophagus  is  a flexible  tube,  which,  when  distend- 
ed, is  nearly  cylindrical.  It  consists  of  a muscular  coat 
externally,  and  an  internal  tunic  evidently  continued  from 
that  of  the  pharynx.  These  coats  are  connected  by  a cel- 
lular substance  called  the  Nervous  Coat , which  is  remark- 
ably loose,  and  allows  them  to  move  considerably  upon 
each  other.  The  muscular  coat,  which  is  very  distinguish- 
able from  that  of  the  pharynx,  consists  of  two  substantial 


See  page  38. 


96 


The  Oesophagus. 

strata  of  fibres;  the  exterior  of  which  is  nearly  longitudi- 
nal in  its  direction,  and  the  interior  circular  or  transverse. 

The  internal  coat  of  the  oesophagus,  resembling  that  of 
the  fauces,  is  soft  and  spongy.  It  is  covered  with  a very 
delicate  cuticle,  which  Haller  supposed  to  be  too  tender 
to  confine  the  matter  of  variolous  pustules,  as  he  had  never 
found  these  extending  into  the  oesophagus.  It  is  very  vascu- 
lar, and  abounds  with  the  orifices  of  mucous  follicles,  from 
which  is  constantly  poured  out  the  mucus  that  is  spread 
over  this  surface.  When  the  oesophagus  is  not  distended, 
many  longitudinal  plaits  are  found  in  this  membrane  by 
the  contraction  of  the  circular  or  transverse  fibres  exterior 
to  it.  These  plaits  are  calculated  to  admit  readily  of  the 
distention  which  is  requisite  in  deglutition.  This  tunic  is 
continued  from  the  lining  membrane  of  the  pharynx  above, 
and  terminates  below  in  the  villous  coat  of  the  stomach; 
from  which,  however,  it  is  very  different. 

The  bloodvessels  of  the  (Esophagus  come  from  those 
which  are  in  the  vicinity.  The  nerves  are  derived  from 
the  eighth  pair.  The  lymphatic  ve^els  are  very  abundant. 

In  the  neck,  the  (Esophagus  inclines  rather  to  the  left  of 
the  middle  line.  As  it  proceeds  down  the  back  between 
the  laminae  of  the  mediastinum,  it  preserves  the  same 
course  to  the  fourth  dorsal  vertebra,  when  it  assumes  the 
middle  portion  and  proceeds  downwards,  with  the  aorta 
to  its  left,  and  the  pericardium  before  it.  About  the  ninth 
dorsal  vertebra  it  inclines  again  rather  to  the  left,  and 
somewhat  forward,  to  arrive  at  the  aperture  in  the  dia- 
phragm through  which  it  passes. 

Throughout  this  course  it  is  connected  by  cellular  mem- 
brane to  the  contiguous  parts;  and  this  investiture  of  cel- 
lular membrane  has  been  called  its  External  Coat. 


&7 


Form  of  the  Stomach. 

While  the  oesophagus  is  in  the  posterior  mediastinum, 
it  is  in  contact  with  several  small  absorbent  glands,  espe- 
cially when  it  first  assumes  a situation  to  the  right  of  the 
aorta.  These  glands  were  formerly  believed  to  be  particu- 
larly connected  with  this  tube,  but  they  are  now  considered 
as  belonging  to  the  absorbent  system.  They  are  sometimes 
greatly  enlarged. 

SECTION  II. 

Of  the  Stomach. 

THIS  most  important  organ,  which  occasionally  exerts 
a powerful  influence  upon  every  part  of  the  body,  appears 
very  simple  in  its  structure. 

It  is  a large  sac,  which  is  so  thin  when  much  inflated, 
that  at  first  view  it  seems  membranous,  but  upon  exami- 
nation is  found  to  be  composed  of  several  laminae  or  coats, 
each  of  a different  structure.  It  is  of  considerable  length, 
but  incurvated.  It  is  much  larger  at  one  extremity  than  the 
other,  and  changes  so  gradually  in  this  respect,  that  it 
would  appear  conical  if  it  were  straight.  It  is  not,  how- 
ever, strictly  conical,  unless  it  is  greatly  distended;  for 
when  moderately  distended,  a transverse  section  is 
rather  oval  than  circular.  It  is  therefore  considered  as 
having  two  broad  sides  or  surfaces,  and  two  edges,  which 
are  the  curvatures.  It  has  been  compared  by  the  anato- 
mists of  different  nations  to  the  wind  sac  of  the  musical 
instrument  called  the  bag-pipe.*  The  orifice  in  which  the 
oesophagus  terminates  is  at  a small  distance  from  its  largest 

* The  student  ought  not  to  attempt  to  acquire  an  idea  of  the  form  of 
the  stomach  without  demonstration,  for  a view  of  one  moment  will  be 
more  serviceable  than  a long  description. 

Vol.  II.  N 


98 


Position  of  the  Stomach . 

extremity,  and  is  called  Cardia.  The  orifice  which  com- 
municates with  the  intestines  is  at  the  termination  of  its 
small  incurvated  extremity,  and  is  called  the  Pylorus. 

The  two  ends  of  the  stomach  being  thus  very  different 
in  size,  are  denominated  the  great  and  small  extremities. 
The  two  curved  portions  of  the  surface  are  also  called  the 
great  and  small  curvatures.  The  two  flat  portions  of  the 
surface,  or  the  broadsides,  are  called  the  anterior  and  pos- 
terior surfaces. 

The  situation  of  the  stomach  in  the  abdomen  is  nearly 
transverse:  it  lies  principally  in  the  left  hypochondriac  and 
the  epigastric  regions,  immediately  below  the  liver.  The 
great  extremity  of  the  stomach  is  in  the  left  hypochon- 
driac region,  and  the  lesser  extremity  in  the  epigastric 
region,  under  the  left  lobe  of  the  liver.  The  upper  orifice, 
or  Cardia , is  nearly  opposite  to  the  body  of  the  last  dorsal 
vertebra;  and,  owing  to  the  curved  form  of  the  stomach, 
the  other  orifice,  or  Pylorus , is  situated  at  a small  distance 
to  the  right  of  that  bone,  and  rather  lower  and  more  for- 
ward than  the  cardia:  both  orifices  being  in  the  epigastric 
region.  The  position  of  the  stomach  is  oblique  in  two  res- 
pects; it  inclines  in  a small  degree  from  above  downwards, 
from  the  left  to  the  right;  and  it  also  inclines  downwards 
and  forwards,  from  behind.  Its  two  orifices  are  situated 
obliquely  with  respect  to  each  other;  for,  if  the  stomach, 
when  placed  with  its  small  curvature  upwards,  were  di- 
vided into  two  equal  parts  by  a vertical  plane  passing 
lengthways  through  it,  they  would  be  found  on  different 
sides  of  the  plane. 

As  the  oesophagus  terminates  in  the  stomach  immedi- 
ately after  it  has  passed  through  an  aperture  of  the  dia- 
phragm, it  is  evident  that  the  stomach  must  be  somewhat 
fixed  at  that  place;  but  it  is  more  movable  at  its  other 


Changes  in  the  Position  of  the  Stomach.  99 

orifice;  for  the  extremity  of  the  duodenum,  into  which  it 
is  continued,  is  movable. 

The  stomach  is  connected  to  the  concave  surface  of  the 
fiver  by  the  reflexion  or  continuation  of  the  peritoneum, 
which  forms  the  lesser  omentum.  This  membrane,  after 
extending  over  each  surface  of  the  stomach,  continues 
from  its  great  curve  in  the  form  of  the  large  omentum, 
and  connects  it  to  different  parts,  especially  to  the  colon. 
There  are  likewise  folds  of  the  peritoneum,  as  it  passes 
from  the  diaphragm  and  from  the  spleen  to  the  stomach, 
which  appear  like  ligaments. 

Notwithstanding  these  various  connections,  the  stomach 
undergoes  considerable  changes  in  its  position.  When  it  is 
nearly  empty,  and  the  intestines  are  in  the  same  situation, 
its  broad  surfaces  are  presented  forwards  and  backwards; 
but  when  it  is  distended,  these  surfaces  are  presented 
obliquely  upwards  and  downwards,  and  the  great  curva- 
ture forwards.  When  its  anterior  surface  is  presented  up- 
wards, its  orifices  are  considerably  influenced  in  their 
direction,  and  the  oesophagus  forms  an  angle  with  the 
plane  of  the  stomach. 

The  stomach  is  composed  of  four  dissimilar  laminae, 
which  may  be  demonstrated  by  a simple  process  of  dis- 
section. 

There  is  first  a coat  or  external  covering  continued 
from  the  peritoneum:  within  this,  and  connected  to  it  by 
delicate  cellular  substance,  is  a coat  or  stratum  of  muscu- 
lar fibres:  contiguous  to  these  fibres,  internally,  is  a layer 
of  dense  cellular  substance,  called  a nervous  coat;  and  last  is 
the  internal  coat  of  the  stomach,  called  villous,  or  fungous, 
from  the  structure  of  its  surface. 

The  external  or  first  coat  of  the  stomach,  as  has  been 
already  stated,  is  continued  from  the  concave  surface  of 


100  External  Coat  of  the  Stomach. 

the  liver  to  the  lesser  curve  of  the  stomach  in  two  delicate 
laminae,  which  separate  when  they  approach  the  stomach, 
and  pass  down,  one  on  each  side  of  it,  adhering  firmly  to 
it  in  their  course:  at  the  opposite  curve  of  the  stomach 
they  again  unite  to  form  the  great  omentum.  The  stomach 
is  therefore  closely  invested  by  the  peritoneum  on  every 
part  of  its  surface  except  two  strips,  one  at  the  lesser  and 
the  other  at  the  greater  curvature.  These  strips  or  unco- 
vered places  are  formed  by  the  separation  of  the  laminse 
above  mentioned,  which  includes  a triangular  space  bound- 
ed by  the  stomach  and  these  two  laminae.  In  these  trian- 
gular spaces,  at  each  curvature  of  the  stomach,  are  situated 
the  bloodvessels  which  run  along  the  stomach  in  those  di- 
rections, and  also  the  glands  which  belong  to  the  absorbent 
vessels  of  this  viscus.  The  peculiar  arrangement  of  the  la- 
minae at  this  place  is  particularly  calculated  to  permit  the 
dilatation  of  the  stomach.  When  it  is  dilated  the  laminae 
are  in  close  contact  with  its  surface,  and  the  bloodvessels 
being  in  the  angle  formed  by  the  adhesion  of  the  two  la- 
minae to  each  other,  are  so  likewise:  when  it  contracts, 
the  bloodvessels  appear  to  recede  from  it,  and  the  laminae 
are  then  applied  to  each  other. 

Where  the  peritoneum  thus  forms  a coat  to  the  stomach, 
it  is  stronger  and  thicker  than  it  is  between  the  liver  and 
stomach.  In  a recent  subject  it  is  very  smooth  and  moist, 
but  so  thin  that  the  muscular  fibres,  bloodvessels,  &c.  ap- 
pear through  it.  If  it  is  carefully  dissected  from  the  mus- 
cular coat,  it  appears  somewhat  flocculent  on  that  surface 
which  adhered  to  the  muscular  fibres.  It  seems  to  be  most 
abundantly  furnished  with  serous  vessels;  but  it  has  been 
asserted  by  Mascagni  and  Soemmering,  that  a large  pro- 
portion of  its  texture  consists  of  absorbent  vessels.  The 
cellular  substance  which  connects  this  to  the  muscular 


Muscular  and  Nervous  Coats  of  the  Stomach . 101 

coat  appears  no  way  different  from  ordinary  cellular  mem- 
brane. 

The  Muscular  Coat  of  the  stomach  has  been  described 
very  differently  by  respectable  anatomists;  some  consider- 
ing it  as  forming  three  strata  of  fibres,  and  others  but  two. 
If  the  stomach  and  a portion  of  the  oesophagus  attached  to 
it  be  moderately  distended  with  air,  and  the  external  coat 
carefully  dissected  away,  many  longitudinal  fibres  will 
appear  on  every  part  of  it,  that  evidently  proceed  from  the 
oesophagus:  these  fibres  are  particularly  numerous  and 
strong  on  the  lesser  curvature  of  the  stomach.  Besides  the 
longitudinal  fibres  there  are  many  that  have  a circular  di- 
rection, and  these  are  particularly  numerous  towards  the 
small  extremity;  but  it  has  been  doubted  whether  there 
are  any  fibres  in  the  muscular  coat  of  the  stomach  that  go 
directly  round  it.  The  whole  surface  of  the  stomach,  when 
the  peritoneal  coat  is  removed,  appears  at  first  view  to  be 
uniformly  covered  by  muscular  fibres;  but  upon  close  ex- 
amination there  are  interstices  perceived,  which  are  occu- 
pied with  firm  cellular  membrane. 

In  contact  with  the  internal  surface  of  the  muscular 
coat  is  the  cellular  stratum , which  has  been  called  the 
Nervous  Coat  of  the  stomach.  It  is  dense  and  firm,  of  a 
whitish  color,  resembling  condensed  cellular  membrane. 
It  was  considered  as  different  from  ordinary  cellular 
membrane;  but  if  air  be  insinuated  into  its  texture,  by 
blowing  between  the  muscular  and  villous  coats,  while  it 
connects  them  to  each  other,  it  exhibits  the  proper  ap- 
pearance of  cellular  substance.  It  however  adds  greatly  to 
the  general  strength  of  the  stomach,  and  the  vessels  which 
terminate  in  the  villous  coat  ramify  in  it. 

The  internal  coat  of  the  stomach  in  the  dead  subject  is 
commonly  of  a whitish  color,  with  a tinge  of  red.  It  is 


102  Internal  Coat  of  the  Stomach. 

named  villous,  from  its  supposed  resemblance  to  the  sur- 
face of  velvet.  It  has  also  been  called  fungous,  because  the 
processes  analogous  to  the  villi  are  extremely  short,  and 
its  surface  has  a granulated  appearance;  differing  in  these 
respects  from  the  internal  surface  of  the  intestines.  It  is 
continued  from  the  lining  membrane  of  the  (Esophagus, 
but  is  very  different  in  its  structure.  Many  very  small 
vessels  seem  to  enter  into  its  texture,  which  are  derived 
from  branches  that  ramify  in  the  nervous  coat.  It  is  sup- 
posed by  several  anatomists  of  the  highest  authority,  to 
have  a cuticle  or  epithelium;  and  it  is  said  that  such  a 
membrane  has  been  separated  by  disease.  It  ought,  how- 
ever, to  be  remembered,  that  the  structure  of  the  villous 
coat  of  the  stomach  and  intestines,  is  essentially  different 
from  the  structure  of  the  cuticle. 

The  internal  coat  of  the  stomach  is  generally  found  co- 
vered, or  spread  over,  with  mucus,  which  can  be  readily 
scraped  off.  This  mucus  is  certainly  effused  upon  it  by 
secreting  organs,  and  it  has  been  supposed  that  there  were 
small  glandular  bodies  exterior  to  the  villous  coat,  which 
furnished  this  secretion;  but  the  existence  of  such  bodies 
is  very  doubtful,  as  many  skilful  anatomists  have  not  met 
with  any  appearance  that  could  be  taken  for  glands,  except 
in  a very  few  instances,  which  would  not  be  the  case  if 
those  appearances  had  been  natural.  Pores,  perhaps  the 
orifices  of  mucous  follicles,  and  also  of  exhalent  vessels, 
are  very  numerous;  but  no  proper  glandular  masses  are 
attached  to  them.  Glands,  as  have  been  already  said,  are 
found  in  the  triangular  spaces  between  the  laminae  of  the 
peritoneum  at  the  great  and  small  curvatures  of  the  sto- 
mach, but  these  evidently  belong  to  the  absorbent  system. 
Besides  the  mucus  above  mentioned,  a large  quantity  of  a 
different  liquor,  the  proper  Gastric  Juice , or  fluid  of  the 


103 


Gastric  Liquor. 

stomach,  is  effused  from  its  surface.  It  has  been  supposed 
that  this  fluid  is  furnished  by  the  small  glandular  bodies 
believed  to  exist  between  the  coats  of  this  organ;  but,  ad- 
mitting the  existence  of  these  glands,  they  are  not  suffi- 
ciently numerous  to  produce  so  much  of  it  as  is  found, 
and  it  is  therefore  probable  that  this  fluid  is  discharged 
from  the  orifices  of  exhalent  vessels  in  the  internal  surface. 

Much  information  respecting  the  gastric  liquor  has 
been  obtained  within  a few  years  past  by  the  researches 
of  physiologists,  and  they  are  generally  agreed  that  it  is 
the  principal  agent  in  the  effects  produced  by  the  stomach 
upon  alimentary  substances.* 

As  the  muscular  coat  of  the  stomach  frequently  varies 
its  dimensions,  the  villous  and  nervous  coats,  which  have 
no  such  power  of  contraction,  cannot  exactly  fit  it.  They 
therefore  generally  appear  larger,  and  of  course  are 
thrown  into  folds  or  rugae.  These  folds  are  commonly  in 
a longitudinal  direction;  but  at  the  orifices  of  the  stomach 
they  are  arranged  in  a radiated  manner,  and  sometimes 
they  are  observed  in  a transverse  direction.  They  depend 

* On  this  subject  the  student  may  consult  with  advantage, 

M.  Reaumur.  In  the  Memoirs  of  the  Academy  of  Sciences  for  1752. 

John  Hunter.  London  Philosophical  Transactions  for  1772;  and  also 
his  Observations  on  the  Animal  Economy,  1786. 

Dr.  Edward  Stevens.  Inaugural  Thesis  De  Alimentorum  Concoc- 
tione.  Edinburgh,  1777- 

The  Abbe  Spalanzani.  Dissertations  relative  to  Natural  History,  &e. 
The  first  volume  of  the  English  translation  contains  the  author’s  disser- 
tations on  digestion,  and  also  the  first  paper  of  Mr.  Hunter,  and  the 
Thesis  of  Dr.  Stevens,  as  well  as  an  account  of  the  experiments  of  Mr. 
Gosse  of  Geneva. 

In  addition  to  these  there  are  several  interesting  essays  in  the 
French,  German  and  Italian  languages,  a compilation  of  which  is  to  be 
found  in  Johnson’s  “ History  of  the  progress  and  present  state  of  Ani- 
mal Chemistry.”  See  Vol.  I.  page  180. 


104 


The  Pylorus. 

upon  the  contraction  of  the  muscular  fibres,  and  disappear 
entirely  when  the  stomach  is  laid  open  and  spread  out. 

At  the  lower  orifice  is  a circular  fold,  which  is  perma- 
nent, and  constitutes  the  valve  denominated  Pylorus.  It 
appears  like  a circular  septum  with  a large  foramen  in  its 
center,  or  like  a flat  ring.  The  villous  and  nervous  coats  of 
the  stomach  contribute  to  this,  merely  by  forming  the 
circular  fold  or  ruga;  and  within  this  fold  is  a ring  of 
muscular  fibres,  evidently  connected  with  the  circular 
fibres  of  the  muscular  coat  of  the  stomach,  the  diameter  of 
which  at  this  place  is  not  larger  than  that  of  an  intestine: 
the  fibres  of  this  ring  seem  a part  of  the  muscular  coat  pro- 
jecting into  the  cavity  of  the  stomach  and  duodenum.  If  a 
portion  of  the  lesser  extremity  of  the  stomach  and  the 
adjoining  part  of  the  duodenum  be  detached,  and  laid 
open  by  a longitudinal  incision,  and  then  spread  out  upon 
a board,  the  internal  coat  can  be  very  easily  dissected 
from  the  muscular,  and  the  pylorus  will  then  appear  like 
a ridge  or  narrow  bundle  of  muscular  fibres,  which  runs 
across  the  extended  muscular  membrane.  It  is  evident 
that  when  the  parts  are  replaced  so  as  to  form  a cylinder, 
this  narrow  fasciculus  will  form  a ring  in  it.  Thus  ar- 
ranged, the  circular  fibres  can  readily  close  the  lower  ori- 
fice of  the  stomach. 

The  pylorus  separates  the  stomach  from  the  intestine 
duodenum;  and  this  separation  is  marked  exteriorly  by  a 
small  circular  depression,  which  corresponds  exactly  with 
the  situation  of  the  pylorus. 

The  arteries  of  the  stomach  are  derived  from  the  Cceliac , 
the  first  branch  which  the  aorta  sends  off  to  the  viscera  of 
the  abdomen.  This  great  artery,  immediately  after  it 
leaves  the  aorta,  is  divided  into  three  branches,  which  are 
distributed  to  the  stomach,  the  liver,  and  the  spleen,  and 


Lymphatics  and  Nerves  of  the  Stomach.  105 

are  called  the  Superior  Coronary  or  Gastric , the  Hepatic , 
and  the  Splenic.  Besides  the  first  mentioned  branch,  which 
is  distributed  principally  to  the  neighborhood  of  the  car- 
dia  and  to  the  lesser  curvature,  the  stomach  receives  a 
considerable  branch  from  the  hepatic,  which  passes  along 
the  right  portion  of  its  great  curvature,  and  has  been  called 
the  right  gastro-epiploic,  and  another  from  the  spleen, 
which  passes  along  the  left  portion  of  the  great  curvature, 
and  has  been  called  the  left  gastro-epiploic.  In  addition  to 
these  branches,  the  splenic  artery,  before  it  enters  the 
spleen,  sends  off  several  small  arteries  to  the  great  extre- 
mity of  the  stomach,  which  are  called  vasa  brevia. 

These  vasa  brevia  generally  arise  from  the  main  trunk 
of  the  splenic  artery,  but  sometimes  from  its  branches. 

The  veins  which  receive  the  blood  from  these  arteri&s 
have  similar  names,  and  pursue  corresponding  courses 
backwards;  but  they  terminate  in  the  vena  portarum. 

The  absorbent  vessels  of  the  stomach  are  very  numer- 
ous and  large:  they  pass  to  the  glands  which  are  on  the  two 
curvatures,  and  from  thence  to  the  thoracic  duct.  It  is  an 
important  fact  relative  to  the  history  of  digestion,  that 
there  are  good  reasons  for  doubting  whether  chyle  com- 
monly passes  through  them,  notwithstanding  their  number 
and  size.* 

The  nerves  of  the  stomach  are  derived  principally  from 
the  two  great  branches  of  the  par  vagum,  which  accom- 
pany the  oesophagus  and  are  mostly  spent  upon  this  organ. 
It  also  receives  branches  from  several  plexuses,  which  are 
derived  from  the  splanchnic  portions  of  the  intercostal 
nerves. 

* Sabatier,  however,  in  one  subject  observed  white  lines  on  the  stQ- 
ihach,  which  he  suspected  to  be  lacteals.  See  his  account  of  the  absor- 
bents of  the  stomach. 

Voi..  II. 


o 


106 


The  Intestines  in  general. 


SECTION  III. 

Of  the  Intestines. 

THE  intestines  form  a continued  canal  from  the  pylorus 
to  the  anus,  which  is  generally  six  times  the  length  of  the 
subject  to  which  they  belong.  Although  the  different  parts 
of  this  tube  appear  somewhat  different  from  each  other, 
they  agree  in  their  general  structure.  The  coats  or  laminse 
of  which  they  are  composed  are  much  like  those  of  the 
stomach,  but  the  peritoneum  which  forms  their  external 
coat  does  not  approach  them  in  the  same  manner;  nor  is  it 
continued  in  the  form  of  omentum  from  the  whole  tube, 
there  being  only  a certain  portion  of  intestine,  viz.  the 
colon,  from  which  such  a process  of  peritoneum  is  con- 
tinued. 

The  Muscular  Coat,  like  that  of  the  stomach,  consists  of 
two  strata,  the  exterior  of  which  is  composed  of  longitu- 
dinal fibres,  which  adhere  to  the  external  coat,  and  do  not 
appear  very  strong.  The  other  stratum,  consisting  of  cir- 
cular or  transverse  fibres,  is  stronger,  as  the  fibres  are  more 
numerous.  It  is  observable  that  they  adhere  to  the  longi- 
tudinal fibres:  and  they  seldom  if  ever  form  complete 
circles. 

The  cellular  substance  immediately  within  the  muscular 
fibres  resembles  the  nervous  coat  of  the  stomach  in  its 
firmness  and  density.  It  is  likewise  so  arranged  as  to  form 
many  circular  ridges  on  its  internal  surface,  which  support 
to  a certain  degree  the  permanent  circular  plaits  of  the  in- 
ternal coat,  called  valvulse  conniventes. 

The  inner  surface  of  the  internal  coat  has  been  com- 
monly compared  to  that  of  velvet,  and  the  coat  is  there- 
fore called  villous;  but  there  is  certainly  a considerable 


107 


VUlous  Coat  of  the  Intestines . 

difference  between  these  surfaces;  for  if  a portion  of  the 
small  intestine  be  inverted,  and  then  suspended  in  perfectly 
transparent  water,  in  a clear  glass,  and  examined  with  a 
strong  light,  it  will  appear  like  the  external  surface  of  the 
skin  of  a peach,  on  which  the  down  or  hair-like  processes 
are  not  so  close  as  those  on  velvet.  On  this  surface,  be- 
tween the  villi,  there  are  many  orifices  of  mucous  follicles 
and  of  exhaling  vessels.*  Exterior  to  the  villous  coat,  many 
very  small  glandular  bodies  are  sometimes  found,  which 
are  called  after  their  describers  Glandulas  Brunneri  and 
Peyeri. 

The  internal  coat  of  the  upper  portion  of  the  intestinal 
tube  is  arranged  so  as  to  form  a great  number  of  trans- 
verse or  circular  folds  or  plaits,  called  Valvulm  Conni - 
ventes , which  do  not  generally  extend  round  the  intestine, 
but  are  segments  of  circles;  they  are  so  near  each  other 
that  their  internal  edges,  which  are  very  movable,  may  be 
laid  upon  the  folds  next  to  them,  like  tiles  or  shingles.  It 
is  evident  that  this  arrangement  of  the  internal  coat  must 
add  greatly  to  its  length.  This  coat  is  extremely  vascular, 
so  that  in  the  dead  subject  it  can  be  uniformly  colored  by 
a successful  injection.  The  minute  structure  of  it  has  been 
the  subject  of  very  diligent  inquiry.  There  can  be  no  doubt 
but  that  an  immense  number  of  exhaling  and  of  absorbent 
vessels  open  upon  it;  but  there  are  many  different  opinions 
respecting  the  termination  of  one  set  of  vessels  and  the 
commencement  of  the  other. 

* It  appears  clearly,  from  the  account  of  Lieberkuhn,  that  the  ori- 
fices or  terminations  of  the  arteries  on  the  intestines,  are  distinct  from 
the  follicles;  for  he  forced  injection  from  the  arteries  into  the  cavity  of 
the  intestines,  and  found  the  follicles  still  filled  with  mucus.  He  then 
urged  the  injection  further,  and  filled  the  follicles,  or  forced  the  mucus 
out  of  them- 


108  Lieberkuhn  on  the  Villous  Coat. 

A very  interesting  account  of  the  Villous  Coat  was  pub* 
lished  in  1744,  by  Lieberkuhn,  who  was  considered  by  his 
cotemporaries  as  a most  expert  practical  anatomist,  and 
was  also  very  skilful  in  microscopical  examinations,  for 
which  he  was  particularly  calculated,  as  his  natural  powers 
of  vision  were  uncommonly  strong.  In  this  essay  he  refers 
to  his  preparations,  which  were  at  Berlin,  and  which  ap- 
pear to  have  excited  great  surprise  in  the  minds  of  the 
members  of  the  Academy  of  Sciences  of  Prussia,  at  a time 
when  one  of  the  first  anatomists  of  Europe,  the  celebrated 
Meckel,  was  of  their  number. 

According  to  this  account,  the  internal  surface  of  the 
small  intestines  abound  with  villi,  and  with  the  orifices  of 
follicles.  These  villi  are  about  the  fifth  part  of  a line  in 
breadth.  In  each  of  them  is  a cavity  filled  with  a soft 
spongy  substance,  which  has  one  or  more  orifices  com- 
municating with  the  intestines,  and  from  which  also  pro- 
ceeds a lacteal  vessel.  On  the  membrane  which  forms  this 
cavity,  bloodvessels  are  most  minutely  ramified.  This  ca- 
vity he  calls  an  ampullula,  and  supposes  it  to  constitute  the 
principal  part  of  the  villus.  By  injecting  the  arteries  of  the 
intestine,  he  was  able  to  pass  a fluid  through  the  ampul- 
lula into  the  cavity  of  the  gut;  he  kept  a stream  of  air  in 
this  way  passing  through  the  ampullula,  until  it  was  nearly 
dry  and  stiff,  and  then  laid  it  open  with  a fine  instrument. 
From  the  appearances  which  then  presented,  he  inferred 
that  the  cavity  of  the  ampullula  was  occupied  with  a 
spongy  or  cellular  substance.  Around  each  villus  he  found 
a number  of  mucous  follicles,  which  often  were  filled  with 
a tenacious  mucus:  and  distinct  from  these  must  be  the 
exhalent  orifices,  which  discharged  a fluid  injected  by  the 
arteries  without  passing  through  the  mucus  follicles. 

Lieberkuhn  died  early,  and  left  but  one  essay  on  this 


Hewson  and  others  on  the  Villi.  109 

subject,  which  was  originally  published  in  Holland,  in 
1744,  but  has  been  republished  by  the  Academy  of  Ber- 
lin, in  their  Memoirs;  and  also  by  Mr.  John  Sheldon,  of 
London. 

This  account  of  Lieberkuhn  appears  to  have  been  ad- 
mitted by  Haller;  but  it  has  been  rigidly  scrutinized  by 
some  of  the  anatomists  of  London,  who  were  particularly 
interested  with  the  subject;  as  they  had  paid  great  atten- 
tion to  the  absorbent  system,  and  were  very  successful  in 
the  investigation  of  it. 

The  late  Mr.  Hewson,  whose  opinion  is  entitled  to  the 
greatest  respect,  rejected  the  idea  of  the  ampullula,  and  be- 
lieved that  the  villi  are  composed  of  networks  of  lacteals, 
as  well  as  arteries  and  veins;  although  he  added  that  “this 
is  the  only  circumstance  concerning  these  parts  in  which 
he  should  differ  from  this  very  acute  observer.”* 

Mr.  Sheldon  agrees  with  Lieberkuhn:  but  Mr.  Cruik- 
shanks  asserts,  that,  “ in  some  hundred  villi,  he  has  seen 
the  lacteals  originate  by  radiated  branches,  whose  orifices 
were  distinct,  on  the  surface  of  the  villus.”  The  villus 
being  transparent,  when  the  intestine  was  immersed  in 
water,  these  branches,  filled  with  chyle,  could  be  seen 
passing  into  the  lacteal.  Mr.  Cruikshank  therefore  sup- 
poses that  Lieberkuhn  was  mistaken,  and  that  the  spongy 
cavity,  or  ampullula,  was  the  common  cellular  membrane, 
connecting  together  all  the  arteries,  veins,  nerves,  and 
lacteals. 

It  seems  probable,  from  Mr.  Cruikshanks’  statement, 
that  Dr.  William  Hunter  held  the  same  opinion  with  him- 
self. And  there  is  also  reason  to  believe  that  Monro  the 


* See  He  wson’s  Experimental  Inquiries,  vol.  2,  page  171. 


110 


Fyfe  and  others  on  the  Villi . 

second,  who  studied  anatomy  at  Berlin,  held  a different 
opinion  from  Lieberkuhn. 

Mr.  Fyfe,  who  has  been  much  employed  in  the  investi- 
gation of  the  absorbent  system,  and  must  be  perfectly  ac- 
quainted with  the  preparations  of  Monro,  asserts  that 
each  lacteal  takes  its  rise  upon  one  of  the  villi  by  numer- 
ous short  radiated  branches,  and  each  branch  is  furnished 
with  an  orifice  for  imbibing  chyle. 

Several  of  the  late  French  writers  adopt  the  opinion  of 
Lieberkuhn;  but  his  countryman  Soemmering  gives  a 
different  account  of  the  subject.  He  says,  that,  besides  the 
bloodvessels,  each  villus  consists  of  a fine  net-work  of  abr 
sorbent  vessels,  whose  orifices  may  be  distinctly  recog- 
nized; and  that  from  six  to  ten  of  these  orifices  are  some- 
times discovered. 

Mascagni,  who  has  published  the  most  extensive  work 
upon  the  absorbent  system  that  has  yet  appeared,  supposes 
Lieberkuhn  to  have  been  mistaken,  and  confirms  the  des- 
cription of  Hewson:  but  he  also  agrees  with  Hewson  in 
his  opinion  of  the  general  accuracy  of  Lieberkuhn. 

Notwithstanding  their  differences  respecting  the  origin 
of  the  lacteals,  all  these  observers  have  agreed,  that  the 
orifices  which  communicate  with  the  lacteals  are  on  the 
villi;  and  that  these  villi  contain  also  very  fine  ramifica- 
tions of  bloodvessels.  They  have  also  agreed,  that  the 
surface  of  the  intestine  in  the  intervals  of  the  villi  seems 
occupied  with  the  orifices  of  ducts  or  of  exhalent  vessels.* 

* On  this  subject  the  student  will  consult,  with  advantage.  He wson’e 
Experimental  Inquiries,  vol.  2d;  Sheldon’s  history  of  the  Absorbent 
System,  part  1st;  Cruikshanks  on  the  Anatomy  of  the  Absorbing  Ves- 
sels; and  the  Historia  Vasorum  Lymphaticorum  Corporis  Humani,  of 

Mascagni. 


Ill 


Division  of  the  Intestines. 

Although  there  is  a considerable  degree  of  uniformity 
in  the  structure  of  the  intestinal  canal,  different  parts  of 
it  are  very  distinguishable  from  each  other  by  their  exte- 
rior appearance,  by  their  size,  their  investments,  and  their 
position. 

The  first  division  is  into  two  great  portions,  which 
are  very  different  from  each  other  in  their  diameter  and 
length,  as  well  as  their  situation:  the  first  portion  being 
much  smaller  in  diameter,  and  near  four  times  the  length 
of  the  other. 

These  portions  are  therefore  known  by  the  names  of 
Great  and  Small  Intestines , and  the  line  of  separation  be- 
tween them  is  very  strongly  marked;  for  they  do  not  gra- 
dually change  into  each  other,  but  the  alteration  in  size 
and  in  exterior  appearance  is  very  abrupt,  and  their  com- 
munication is  not  perfectly  direct.  A considerable  portion 
of  the  Great  Intestine  is  fixed  immovably  in  the  abdomen, 
while  a large  part  of  the  Small  Intestine  is  very  movable. 

Each  of  these  great  portions  of  the  intestinal  tube  is 
subdivided  into  three  parts.  Thus,  in  the  Small  Intestine , 
there  is  a piece  at  the  commencement  called  Duodenum , 
a great  part  of  which  has  no  coat  from  the  peritoneum, 
and  is  immovably  fixed  in  one  situation;  while  all  the  re- 
mainder of  the  small  intestine  has  a uniform  covering 
from  the  peritoneum,  and  is  very  movable.  This  last 
piece,  notwithstanding  its  exterior  uniformity,  is  consi- 
dered as  forming  two  parts.  The  uppermost  two  fifths 
form  one  part,  which  is  called  Jejunum;  and  the  remain- 
der is  called  Ileon.  The  Great  Intestine  commences  in 
the  lower  part  of  the  right  side  of  the  abdomen,  and 
after  proceeding  up  that  side  crosses  over  to  the  left,  along 


1 12  Commencement  of  the  Small  Intestines . 

which  it  descends  to  the  lower  part  again,  when  by  a pe- 
culiar flexure  it  proceeds  to  the  center  of  the  posterior 
margin  of  the  pelvis,  from  which  it  passes  down  to  the 
anus.  A short  portion  of  this  intestine,  which  is  above  its 
junction  with  the  ileon,  is  called  Ccecum ; the  part  which 
proceeds  from  this,  round  the  abdomen,  is  called  Co- 
lon; and  the  portion  which  is  in  the  pelvis  is  called 
Rectum . 

Of  the  Small  Intestines. 

Previous  to  the  description  of  the  small  intestines,  it  is 
necessary  to  observe,  that  the  Mesocolon , or  process  of  the 
peritoneum  connected  to  the  transverse  portion  of  the  co- 
lon, forms  a kind  of  movable  and  incomplete  septum,  which 
divides  the  abdomen  into  an  upper  and  lower  apartment. 
Above  this  septum  are  the  stomach,  with  the  commence- 
ment of  the  duodenum,  the  liver,  and  the  spleen;  below 
it,  that  portion  of  the  small  intestine  which  is  called  jeju- 
num and  ileon,  makes  its  appearance.  The  portion  of  the 
intestine  which  passes  from  the  stomach  to  the  jejunum, 
and  is  called  Duodenum , is  so  much  involved  by  the  me- 
socolon, that  the  greatest  part  of  it  cannot  be  seen  without 
dissecting  the  mesocolon  from  its  connection  with  the  back 
of  the  abdomen.  For  the  duodenum  proceeds  backwards 
from  the  pylorus, and  passing  down  behind  the  peritoneum, 
enters  a vacant  space  between  the  two  laminae  of  the  me- 
socolon; it  proceeds  for  some  distance  in  this  space,  and 
then  emerges  on  the  lower  side  of  the  mesocolon.  Here  the 
duodenum  terminates,  and  the  small  intestine  then  is  in- 
vested by  the  peritoneum  in  such  manner  as  to  form  me- 
sentery, which  continues  with  it  throughout  its  whole 
course  to  the  great  intestine.  This  portion  of  the  intestine, 
although  very  uniform  in  its  exterior  appearance,  as  has 


113 


Situation  of  the  Duodenum.  • 

been  observed  before,  is  divided  into  Jejunum,  and  Ikon: 
the  Jejunum  being  the  upper  portion,  which  begins  at 
the  mesocolon;  and  the  Ileon  the  lower  portion,  which 
opens  into  the  great  intestine. 

Of  the  Duodenum. 

The  length  of  this  intestine  is  equal  to  the  breadth  of 
twelve  fingers,  and  hence  its  name.  It  is  very  different 
from  the  rest  of  the  small  intestine,  not  only  as  respects  its 
position,  and  investment  by  the  peritoneum;  but  on  ac- 
count of  its  connexion  with  the  liver  and  pancreas,  by 
means  of  their  excretory  ducts,  which  open  into  it.  From 
this  oonnexion  with  these  glands,  probably,  all  the  pecu- 
liarities of  its  position  are  to  be  deduced. 

When  the  stomach  is  in  its  natural  situation,  the  pylo- 
rus is  at  some  distance  from  the  back  of  the  abdomen. 
The  duodenum  proceeds  backwards  from  this  point,  and 
passes  near  the  neck  of  the  gall-bladder,  being  here  con- 
nected with  the  small  omentum;  it  then  curves  downwards, 
and  descends  before  the  right  kidney,  sometimes  as  low  as 
the  lower  part  of  it;  then  it  curves  again,  and  passes  over 
to  the  left:  after  it  has  arrived  at  the  left  side  of  the  spine,  at 
the  second  or  third  lumbar  vertebra,  it  projects  forwards 
and  downwards  to  form  the  jejunum.  The  only  portion 
of  this  intestine  which  is  movable,  is  that  which  is  in  sight 
as  it  proceeds  immediately  from  the  duodenum,  being 
about  an  inch  and  a half,  or  two  inches  in  length.  The  re- 
mainder is  connected  to  the  back  of  the  abdomen,  and  lies 
between  the  two  laminae  of  the  mesocolon.  In  its  progress 
it  passes  before  the  aorta  and  the  vena  cava,  but  the  princi- 
pal branch  of  the  vena  portarum  is  before  it. 

The  duodenum  is  larger  in  diameter  than  any  other 
part  of  the  small  intestines,  and  has  a stronger  muscular 
VOL.  II.  P 


114  Orifice#  of  the  Biliary  and  Pancreatic  Duct a. 

coat.  Its  general  situation  admits  of  great  dilatation,  and  it 
has  been  called  a second  stomach.  Its  internal  coat  is 
strictly  villous,  in  the  anatomical  sense  of  the  word;  and 
its  folds,  the  valvulas  conniventes,  begin  at  a small  distance 
from  the  pylorus.  The  orifices  of  many  mucous  ducts  are 
to  be  seen  on  its  surface.  It  is  supposed  that  some  of  these 
are  the  terminations  of  ducts  from  the  glands  of  Brunner, 
which  sometimes  appear  in  the  villous  coat,  or  very  close 
to  it  exteriorly;  being  small  flat  bodies,  with  a depression 
in  the  center,  and  a foramen  in  the  depression.  They  are 
sometimes  very  numerous  at  the  upper  extremity  of  this 
intestine,  and  diminish  gradually  towards  the  other  extre- 
mity. 

The  biliary  and  pancreatic  ducts  open  posteriorly 
into  the  duodenum,  rather  above  the  middle  of  it.  The 
orifice  of  these  ducts  is  generally  surrounded  by  a small 
tubercle,  which  is  oblong,  somewhat  rounded  at  one  ex- 
tremity, and  pointed  at  the  other.  Sometimes  this  orifice 
is  in  a plait,  like  one  of  the  valvulae  conniventes.  Most 
commonly  the  two  ducts  unite  before  they  perforate  the 
coat,  so  as  to  form  but  one  orifice;  and  sometimes  they 
open  separately,  but  always  very  near  to  each  other. 

Absorbent  vessels,  which  contain  chyle,  are  found  on 
the  duodenum. 

The  Jejunum  and  Ileon 

Are  situated  in  the  abdomen  very  differently  from  the 
duodenum.  When  the  cavity  is  opened,  and  the  omentum 
raised,  they  are  in  full  view;  and  every  portion  of  them, 
except  the  two  extremities  and  the  parts  near  them,  can 
readily  be  moved.  This  freedom  of  motion  is  owing  to  the 
manner  in  which  they  are  invested  by  the  peritoneum;  or 
in  the  technical  language  of  anatomy,  to  the  length  of  their 


Distinction  between  'Jejunum  and  Ileon.  115 

mesentery.  They  agree  in  their  structure  with  the  general 
description  of  the  small  intestines,  but  their  muscular  coat 
is  rather  weaker  than  that  of  the  duodenum.  The  valvulse 
conniventes  are  very  numerous  and  large  in  the  upper  part 
of  the  tube,  or  the  jejunum;  and  gradually  diminish  in 
number,  until  they  finally  disappear,  in  the  lower  part  of 
the  ileon.  The  villous  coat  is  in  perfection  in  the  jejunum, 
the  villi  being  more  conspicuous  here  than  in  any  other 
part  of  the  intestinal  tube.  There  are  frequently  found, 
exterior  to  this  coat,  but  intimately  connected  with  it, 
many  small  glandular  bodies  of  a roundish  form,  which 
are  often  clustered  together  at  that  part  of  the  intestine 
which  corresponds  with  the  interstice  of  the  laminse  of  the 
mesentery.  They  are  called  Peyer’s  glands,  after  the  anato- 
mist who  first  described  them;  and  are  supposed,  like 
the  glands  of  Brunner,  to  secrete  mucus.  If  a portion  of 
the  jejunum  be  inverted,  and  moderately  distended  with 
air,  these  bodies  appear  very  distinctly  in  it,  dispersed  at 
small  distances  from  each  other.  In  the  ileon  they  appear 
in  small  clusters,  which  often  have  the  appearance  of 
disease. 

No  natural  line  of  separation  for  distinguishing  the  je- 
junum and  ileon  from  each  other,  is  to  be  found;  but  these 
names  are  still  retained;  and  therefore  a rule  laid  down  by 
Winslow  is  generally  adopted,  viz.  to  name  the  first  two 
fifths  of  the  tube  jejunum,  and  the  remainder  ileon.  There 
are,  however,  some  important  differences  between  these 
portions  of  the  intestine. 

In  the  jejunum,  the  valvulae  conniventes  are  so  numer- 
ous, that  they  lie  in  contact  with  each  other,  as  shingles  on 
the  roof  of  a house;  in  the  ileon  they  gradually  diminish 
in  number,  and  finally  disappear.  In  the  jejunum  the  villi 
are  much  stronger  than  they  are  in  the  ileon* 


116  Arrangement  of  Jejunum  and  Ileon. 

It  is  very  difficult  to  acquire  a precise  idea  of  the  ar- 
rangement of  this  part  of  the  intestinal  tube,  while  it  is  in 
the  abdomen,  especially  if  it  be  much  distended;  but  if  it 
be  separated  at  each  extremity  from  the  intestine  with 
which  it  is  connected,  and  the  mesentery  cut  off  from  the 
back  of  the  abdomen,  and  the  whole  then  spread  out  upon 
a flat  surface,  it  will  appear,  as  has  been  already  said,  that 
the  intestine  is  arranged  so  as  to  form  a semicircle  or  large 
curve;  the  concavity  of  which  is  opposite  to  the  back  of 
the  abdomen,  while  the  convexity  presents  forward.  It 
will  also  appear,  when  thus  placed  upon  a table,  that  the 
intestine,  while  connected  with  the  mesentery,  is  laid  into 
many  folds.  It  has  been  supposed,  that  the  middle  portion 
of  the  mesentery,  and  the  intestine  connected  with  it,  is 
generally  in  the  umbilical  region;  and  the  two  portions  on 
the  sides  of  it  are  in  the  iliac  regions:  but  their  situation 
in  the  abdomen  varies  considerably  at  different  times. 
When  the  viscera  of  the  pelvis  are  empty,  a large  portion 
of  the  small  intestine  is  in  the  pelvis;  but  when  those  vis- 
cera are  fdled,  the  intestine  is  in  the  general  cavity  of  the 
abdomen. 

The  Mesentery 

Is  a process  of  the  peritoneum,  which  is  formed  in  the 
manner  of  a plait  or  fold,  and  of  course  consists  of  two  la- 
minae. These  laminae  proceed  from  the  back  part  of  the 
abdomen,  and  are  so  near  to  each  other,  that  they  compose 
one  substantial  process;  having  cellular  and  adipose  sub- 
stance, bloodvessels  and  nerves,  with  absorbent  or  lacteal 
vessels  and  their  glands,  between  them. 

The  form  of  this  process,  when  it  is  separated  from 
the  back,  and  the  intestines  are  detached  from  it,  is  some- 
what semicircular:  that  portion  of  its  margin  or  edge 


117 


Construction  of  the  Mesentery. 

which  corresponds  to  the  diameter  of  the  semicircle,  is 
connected  to  the  back  of  the  abdomen,  and  called  the  root 
of  the  mesentery;  the  edge,  which  is  the  circumference  of 
the  semicircle,  is  connected  with  the  intestine.  The  edge 
connected  with  the  back  of  the  abdomen  is  commonly 
about  five  or  six  inches  in  length;  the  semicircular  edge, 
instead  of  extending  fifteen  or  eighteen  inches,  the  ordi- 
nary proportion,  is  attached  to  a portion  of  intestine  some- 
times twenty-four  feet  in  length.  The  mesentery,  on  ac- 
count of  this  great  difference  between  its  diameter  and 
circumference,  has  been  compared  to  the  ruffle  of  a shirt- 
sleeve; its  root  being  taken  for  the  plaited  edge  of  the 
ruffle,  and  the  circumference  for  its  loose  edge.  But  the 
comparison  is  not  precisely  accurate;  for  the  mesentery  is 
not  plaited  at  its  root,  but  perfectly  smooth,  and  free  from 
every  kind  of  fold.  It  begins  to  enlarge  towards  its  circum- 
ference, and  enlarges  to  that  degree,  that  it  falls  into  plaits 
or  folds;  precisely  such  as  would  exist  in  a semicircular 
piece  of  membrane  about  six  inches  in  diameter,  if  a 
number  of  simple  incisions,  of  about  an  inch  and  a half 
in  length,  were  made  in  a radiated  direction  from  its  cir- 
cumference, and  if  portions  like  a sextant  or  quadrant 
were  taken  from  a circular  membrane  three  inches  in 
diameter,  and  united  by  their  edges  to  these  incisions,  so 
that  their  circumference  might  be  continuous  with  the 
circumference  of  the  large  semicircular  piece.  In  this 
case,  the  portions  like  quadrants  or  sextants  would  as- 
sume a folded  position  like  the  edge  of  the  mesentery, 
while  the  middle  of  the  semicircular  piece  would  preserve 
its  regular  form  without  folds;  as  is  the  case  with  the  me- 
sentery at  some  distance  within  its  circumference.  By 
many  additions  of  this  kind,  the  circumference  of  a mem- 
brane, which  was  originally  a semicircle  of  five  or  six 


118 


Root  of  the  Mesentery. 

inches,  may  be  extended  so  as  to  exceed  greatly  that  of  the 
mesentery.  It  seems  of  course  impossible  to  form  an  accu- 
rate model  of  the  mesentery  with  a single  piece  of  mem- 
brane or  paper;  but  it  may  be  easily  made  with  clay,  or  any 
ductile  substance.  A model  of  this  kind  must  necessarily  be 
folded  after  the  manner  of  the  mesentery;  and  its  circum- 
ference, like  the  mesentery,  would  appear  as  if  formed  of 
portions  of  the  circumference  of  smaller  circles  united  to 
each  other.* 

The  root  of  the  mesentery  commences  with  the  jeju- 
num on  the  lower  side  of  the  mesocolon,  at  the  left  of  the 
spine,  and  extends  downwards  near  to  the  right  iliac  re- 
gion; crossing  the  spine  obliquely.  When  it  is  examined 
in  its  natural  situation,  the  peritoneum  is  found  continued 
from  the  back  of  the  abdomen  to  the  intestine;  it  then  sur- 
rounds the  intestine,  and  continues  from  it  to  the  back  of 
the  abdomen  again.  There  must  therefore  be  two  laminae 
of  peritoneum  in  the  mesentery,  and  there  must  be  a small 
portion  of  intestine  answering  to  the  interstice  be- 
tween these  laminae,  which  is  not  covered  by  the  perito- 
neum. The  bloodvessels,  and  absorbents  or  lacteals,  pass 
mostcommodiously  to  the  intestines  between  these  laminae; 
for  they  are  connected  with  large  trunks  that  lie  on  or  near 
the  spine,  and  the  root  of  the  mesentery  commences  there. 

The  glands  connected  with  the  lacteals  or  absorbents 
are  very  conspicuous  in  the  mesentery,  and  are  commonly 
called  mesenteric  glands.  They  are  of  different  sizes,  from 
more  than  half  an  inch  to  one  or  two  lines  in  diameter. 
They  are  very  numerous,  and  scattered  irregularly,  but 

* A model,  upon  the  plan  first  mentioned,  was  invented  by  Dr.  J.  G. 
Shippen.  It  has  been  proposed,  I believe  by  M.  Gavard,  to  make  one 
with  a single  piece  of  buckskin,  of  a semicircular  form,  by  stretching  it 
at  the  circumference. 


Appearance  of  the  Caecum  and  Colon.  119 

are  seldom  observed  very  near  to  the  intestine.  They  are 
often  enlarged  in  consequence  of  disease,  especially  iu 
children. 

The  nerves  of  the  small  intestines,  which  are  derived 
principally  from  the  superior  mesenteric  plexus,  are  also 
to  be  found  here. 

The  adipose  matter  between  the  laminae  of  the  mesen- 
tery is  very  often  in  a large  quantity,  but  varies  in  pro- 
portion to  the  general  quantity  of  adeps  in  the  subject. 


Of  the  Great  Intestines. 

The  Caecum  and  Colon 

Are  very  different  from  the  small  intestines  in  many 
respects.  They  are  much  larger  in  diameter.  Their  exter- 
nal surface  is  marked  by  three  longitudinal  bands  of  a 
light  colour,  which  extend  the  greatest  part  of  their  length, 
and  are  placed  nearly  at  equal  distances  from  each  other. 
The  spaces  between  these  bands  are  marked  by  transverse 
indentations,  which  pass  from  one  band  to  the  other  at 
short  but  unequal  distances.  At  these  indentations  the 
coats  of  the  intestine  are  pressed  inwards,  as  if  a fine 
thread  had  been  drawn  round  it  externally,  while  the 
spaces  between  them  are  full  and  tumid,  and  on  this  ac- 
count are  called  cells. 

The  great  intestine,  with  these  appearances,  begins,  as 
has  been  already  observed,  in  the  right  iliac  region,  by  a 
rounded  end  which  rests  on  the  fossa  or  concave  surface 
formed  by  the  costa  of  the  ileum;  from  this  it  is  continued 
upwards  in  the  right  lumbar  region,  anterior  to  the  kid- 
ney, until  it  arrives  near  the  liver,  when  it  forms  a curve, 
and  passes  directly  across  the  abdomen  to  the  left  side.  In 


120  Position  of  the  Caecum. 

this  course  it  approaches  so  near  to  the  under  side  of  the 
liver,  that  it  is  often  in  contact  with  it,  and  with  the  gall- 
bladder, which,  after  death,  tinges  it  with  a yellow  color. 
On  the  left  side  it  passes  down  in  the  lumbar  region,  be- 
fore the  kidney,  to  the  left  iliac  region;  here  it  is  curved 
so  as  to  resemble  the  Roman  letter  S,  inverted;  this 
curve  generally  carries  it  to  the  right  side  of  the  spine, 
and  then  brings  it  back  to  the  center  of  the  sacrum.  Here 
the  intestine  changes  its  course,  and  passing  into  the  pel- 
vis, continues  downward,  in  contact  with  the  sacrum  and 
coccygis,  and  partaking  of  the  curvature  of  those  bones, 
until  it  terminates  at  the  anus,  where  it  is  connected  with 
the  sphincter  and  levator  ani  muscles. 

About  two  inches  from  the  commencement  of  the  great 
intestine  the  ileon  opens  into  it  laterally;  and  all  that  por- 
tion which  is  between  its  commencement  and  the  insertion 
of  the  ileon  is  termed  Caecum , or  the  blind  intestine:  that 
part  of  the  great  tube,  which  is  included  in  its  course 
from  the  insertion  of  the  ileon  to  the  posterior  part  of  the 
brim  of  the  pelvis,  is  called  Colon;  and  the  remainder,  or 
the  part  which  is  contained  in  the  pelvis,  is  termed 
Rectum. 

The  Caecum  is  nearly  as  wide  as  it  is  long;  it  is  fixed  in 
the  right  iliac  fossa  by  the  peritoneum,  which  invests  it  so 
that  the  great  body  of  the  intestine  projects  from  the  sur- 
face of  the  fossa  covered  by  the  peritoneum;  but  a portion 
is  in  close  contact  with  the  surface,  and  connected  to  it  by 
cellular  membrane.  Its  external  surface,  covered  by  the 
peritoneum,  is  marked  by  two  of  the  bands  or  stripes  be- 
fore mentioned,  which  proceed  on  it  lengthways.  These 
bands  are  in  full  view,  but  the  third  band  is  generally  on  that 
part  of  the  intestine  which  rests  on  the  iliac  fossa,  and  is 
therefore  out  of  sight.  At  the  rounded  extremity  of  the 


121 


Structure  of  the  Colon. 

eascum,  situated  anteriorly  and  internally,  is  a small  pro- 
cess resembling  an  earth-worm  in  form  and  size:  this  is 
therefore  called  Appendicula  Vermiformis.  It  is  hollow, 
and  communicates  with  the  cavity  of  the  caecum  at  the 
place  of  junction;  and,  like  the  caecum,  has  its  other  extre- 
mity closed  up.  It  is  composed  of  the  same  number  of 
coats  and  has  the  same  structure  as  the  great  intestine:  its 
length  varies  from  two  to  four  inches. 

The  longitudinal  bands  above  mentioned  commence  at 
the  junction  of  this  appendix  with  the  caecum,  and  conti- 
nue throughout  the  extent  of  the  colon.  They  appear  to 
be  formed  by  some  of  the  longitudinal  fibres  of  the  mus- 
cular coat,  which  are  arranged  close  to  each  other.  These 
fibres  seem  to  be  shorter  than  the  coats  of  the  intestine, 
and  the  interior  coats  adhere  firmly  to  them.  Thus  are 
produced  the  indentations  and  cells;  for  if  the  bands  are 
divided  transversely,  the  indentations  disappear,  and  the 
surface  of  the  intestine  becomes  uniform.  One  of  these 
bands  is  covered  by  the  mesocolon. 

The  circular  or  transverse  fibres  of  the  muscular  coat  of 
the  CcEcum  and  Colon  are  very  delicate,  and  not  numerous. 

The  internal  coat  differs  materially  from  that  of  the 
small  intestines,  although  at  first  view  they  seem  to  re- 
semble each  other;  for  if  a portion  of  the  ileon  and  of  the 
colon  be  inverted  and  suspended  in  water,  no  villi  can  be 
seen  with  the  naked  eye  on  the  internal  coat  of  the  colon, 
while  those  of  the  ileon  are  very  visible.  The  glands  ex- 
terior to  this  coat  are  larger  than  those  on  the  small  in- 
testines. 

Instead  of  valvulse  conniventes,  are  the  ridges  made 
by  the  indentations  or  depressions  above  described,  which 
separate  the  incomplete  cells  from  each  other.  These 
ridges  differ  essentially  from  the  valvulse  conniventes. 

Vox..  II.  Q 


122  Valve  of  the  Colon . 

because  all  the  coats  of  the  intestine  are  concerned  in 
their  formation,  whereas  the  valvulae  conniventes  are 
formed  by  the  villous  coat  only;  they  also  project  into  the 
cavity  of  the  intestine,  while  the  valvulae  are  laid  on  its 
surface.  They  pass  only  from  one  longitudinal  band  to 
another,  and,  in  consequence  of  this,  the  cells  are  small, 
and  the  position  of  each  band  is  very  evident  when  the 
intestine  is  laid  open. 

The  communication  of  the  ileon  with  the  great  intestine 
has  been  already  stated  to  be  on  the  left  side  of  it,  about 
two  inches  from  its  commencement.  The  aperture  is  so 
constructed,  that  it  is  considered  as  a valve,  and  is  called 
the  Valve  of  Bauhin,  or  of  Tulpius,  after  the  anatomists 
who  have  described  it.  The  appearance  of  the  aperture  is 
as  follows:  If  the  caecum,  with  a small  portion  of  the  ileon 
and  of  the  colon,  be  separated  from  the  other  intestines, 
and  kept  in  an  inflated  state  until  it  be  so  dry  as  to  pre- 
serve its  form  when  opened,  and  then  if  the  csecum  and 
colon  be  laid  open  opposite  to  the  aperture  of  the  ileon, 
a large  transverse  ridge,  resembling  some  of  the  ridges  or 
folds  just  described,  will  be  seen  projecting  into  the  cavity 
of  the  intestine.  In  the  internal  edge  of  this  fold  is  a long 
slit  or  opening,  which  forms  the  communication  between 
the  two  intestines.  It  is  obvious  that  the  form  of  this  fold 
must  be  that  of  a crescent;  and  that  its  two  surfaces,  with 
the  slit  between  them,  must  have  the  appearance  of  two 
lips,  which  would  readily  permit  a fluid  or  substance  of 
soft  consistence  to  pass  from  the  ileon  into  the  great  in- 
testines, but  must  impede,  if  not  prevent,  its  passage  back; 
especially  if  the  large  intestines  were  distended,  as  then 
the  lips  would  be  pressed  against  each  other. 

When  the  peritoneal  coat  is  dissected  from  each  of  the 
intestines  at  their  place  of  junction,  and  this  structure  is 


123 


Structure  of  the  Valve  of  the  Colon . 

then  examined  from  without , it  appears  as  if  a transverse 
or  half  circular  indentation  had  been  formed  by  the  villous 
coat  of  the  great  intestine,  and  that  the  internal  coat  of  the 
extremity  of  the  ileon  was  pressed  into  this  indentation, 
and  united  to  the  internal  coat  of  the  great  intestine  which 
formed  it;  while  there  was  a slit,  both  in  the  indentation 
and  in  the  end  of  the  ileon,  which  formed  a communica- 
tion between  the  cavity  of  the  great  intestine  and  the  ileon. 
The  longitudinal  fibres  of  both  intestines,  as  well  as  their 
external  coats,  seemed  to  be  united,  so  as  to  form  a com- 
mon cover  for  them;  while  the  circular  fibres  were  blend- 
ed in  the  two  portions  of  the  indentation  which  form  the 
lips  of  the  orifice. 

This  orifice  is,  of  course,  transverse  with  respect  to  the 
intestine.  It  has  been  observed,  that  there  was  a difference 
in  the  thickness  and  strength  of  the  two  lips  or  valves;  that 
the  lower  valve  was  the  strongest,  and  appeared  to  have 
the  largest  proportion  of  muscular  fibres  in  its  composi- 
tion. At  the  extremities  of  the  orifice,  and  near  each  end  of 
the  fold  or  ridge,  are  tendinous  fibres,  which  give  strength 
to  the  structure;  they  are  called  the  Retinacula  of  Mor- 
gagni, as  they  were  first  described  by  that  anatomist. 

There  is  great  reason  for  believing  that  this  valve  can- 
not prevent  the  retrograde  motion  of  the  contents  of  the 
intestines  in  all  cases;  for  in  some  instances  of  hernia  and 
of  colic,  matter  perfectly  stercoraceous  has  been  vomited, 
and  the  probable  inference  from  such  a state  of  the  ejected 
matter  is,  that  this  matter  has  been  in  the  large  intestines. 
It  is  also  said,  that  suppositories  and  enemata  have  been 
discharged  by  vomiting. 

On  the  right  and  left  sides  of  the  abdomen,  the  colon  is 
in  close  contact  with  the  posterior  surface  of  the  cavity. 
The  peritoneum,  which  covers  this  surface,  extends  over 


124 


Position  of  the  Rectum. 

the  intestine  also,  and  thus  retains  it  in  its  position.  The 
great  arch  of  the  colon,  which  is  loose,  and  moves  far  from 
the  back  of  the  abdomen,  is  invested  by  the  two  laminae  of 
the  omentum,  which,  after  surrounding  it,  unite  again  and 
form  mesocolon.  Connected  with  the  exterior  surface  of 
the  colon  are  many  processes,  composed  of  adipose  mem- 
brane, varying  in  length  from  half  an  inch  to  an  inch  and 
a half:  these  appear  to  be  of  the  nature  of  the  omentum, 
and  are  therefore  generally  denominated  Appendices  Epi- 
ploicce. 

The  Rectum. 

After  forming  the  sigmoid  flexure,  the  colon  termi- 
nates; and  the  rectum  begins  opposite  to  the  lower  sur- 
face of  the  last  lumbar  vertebra,  and  nearly  in  contact  with 
it:  from  this  it  proceeds  downwards,  forming  a curve  like 
the  sacrum,  until  it  terminates  at  the  anus,  where  it  is  in- 
vested with  the  muscles  called  the  sphincter  and  levator 
ani.  It  is  called  rectum,  because  in  this  course  it  is  sup- 
posed not  to  incline  to  either  side;  but  it  is  often  found  on 
one  side  of  the  middle  line.* 

This  intestine  being  in  contact  with  the  posterior  sur- 
face of  the  pelvis,  is  covered,  on  its  anterior  surface  only, 
by  the  peritoneum  which  lines  the  posterior  surface  of  the 
pelvis;  and  it  is  fixed  in  this  situation  by  the  peritoneum, 
as  the  colon  is  on  the  right  and  left  sides  of  the  abdomen, 
but  more  loosely;  and  therefore  the  term  Mesorectum  has 
sometimes  been  applied  to  that  portion  of  the  peritoneum 
which  is  analogous  to  the  mesentery  and  mesocolon. 
The  peritoneum  does  not  extend  to  the  end  of  the  rec- 
tum; for  it  is  reflected  at  the  lower  part  of  the  pelvis  from 

* Morga  gni  and  Haller  supposed  it  to  be  commonly  on  the  left  of  the 
middle  line:  Sabatier  on  the  right. 


125 


Structure  of  the  Rectum. 

the  rectum  to  the  bladder,  or  uterus,  and  does  not  line  the 
bottom  of  the  pelvis;  so  that  the  lower  part  of  this  intes- 
tine, as  well  as  of  the  other  viscera  of  the  pelvis,  is  below 
the  peritoneum,  and  not  connected  with  it. 

The  muscular  coat  of  the  rectum  is  much  thicker  and 
stronger  than  that  of  any  other  intestine.  The  strata  of 
longitudinal  and  circular  fibres  which  compose  it  are  very 
distinct  from  each  other.  The  longitudinal  fibres  are  most 
numerous,  and  terminate  at  the  insertion  of  the  fibres  of 
the  levator  ani  muscle.  The  lower  circular  fibres  are  inti- 
mately connected  with  the  sphincter  ani. 

The  internal  coat  is  very  vascular,  but  the  villous  struc- 
ture is  not  apparent.  Mucous  follicles  are  also  very  numer- 
ous; and  there  are  likewise  some  distinct  glandular  bodies 
exterior  to  this  coat,  which  vary  in  size  in  different  sub- 
jects. 

The  quantity  of  mucus  discharged  from  the  rectum  in 
certain  cases  of  disease,  is  sometimes  very  great.  The  in- 
ternal coat,  in  consequence  of  the  contraction  of  the  circu- 
lar fibres  exterior  to  it,  sometimes  forms  longitudinal 
folds,  which  have  been  called  its  columns;  these  often  dis- 
appear when  the  intestine  is  opened  lengthways  and  spread 
out.  By  the  contraction  of  the  longitudinal  fibres,  the  in- 
ternal coat  is  often  thrown  into  folds  or  doublings,  that 
must  assume  a transverse  or  circular  direction:  they  occa- 
sionally pass  down  through  the  sphincter, and  form  the  pro- 
lapsus ani.  The  rectum  is  most  plentifully  supplied  with 
bloodvessels,  to  be  described  hereafter;  and  it  may  be  ob- 
served, that,  on  the  lower  part  of  the  internal  coat,  the 
veins  are  particularly  numerous. 

The  internal  coat  of  the  rectum  terminates  abruptly  just 
within  the  anus,  and  is  united  to  a production  of  the  skin, 
which,  like  the  covering  of  the  lips,  is  very  delicate  and 


126  Absorbents  and  Nerves  of  the  Intestines. 

vascular,  and  has  an  epithelium,  or  very  thin  cuticle, 
spread  over  it.  The  levator  and  sphincter  ani  muscles, 
with  which  the  termination  of  the  rectum  is  invested,  are 
described  at  page  206,  vol.  I. 

The  Absorbents  of  the  Intestines  are  commonly  deno- 
minated Lacteals.  They  originate  on  the  internal  surfaces 
of  these  viscera,  as  has  been  already  described.  After  pass- 
ing through  the  lymphatic  glands,  which  are  so  numerous 
on  the  mesentery,  they  generally  unite  and  form  one  of 
the  great  trunks  which  compose  the  thoracic  duct.  It  is 
asserted,  that  some  of  the  absorbent  vessels  of  the  lower 
intestines  unite  to  the  lymphatics  of  the  loins. 

The  Nerves  of  the  Intestines  are  principally  derived  from 
the  intercostals,or  great  sympathetics.  From  each  of  these 
nerves,  while  they  are  in  the  thorax,  an  important  branch, 
called  the  ramus  splanchnicus,  arises.  These  splanchnic 
branches  pass  through  the  diaphragm,  and  are  the  chief 
contributors  to  the  ganglions  and  plexuses  formed  in  the 
abdomen.  A plexus  derived  from  this  source  surrounds 
the  superior  mesenteric  artery,  and  another  the  inferior 
mesenteric;  and  from  these  proceed  the  nerves  of  the  in- 
testines. 

The  Omentum 

Requires  a separate  description,  although  several  cir- 
cumstances connected  with  its  structure  have  been  already 
noticed.  It  often  varies  in  its  position;  but  when  it  is  ren- 
dered firm  by  a quantity  of  adipose  matter,  it  is  spread 
over  the  intestines  like  an  apron,  extending  from  the  lower 
edge  or  great  curvature  of  the  stomach  towards  the  bot- 
tom of  the  abdomen. 

As  has  been  already  said,  it  is  an  extension  of  the  peri- 
toneum, in  two  lamina,  from  the  concave  surface  of  the 


Origin  and  Arrangement  of  the  Omentum.  127 

liver  to  the  lesser  curvature  of  the  stomach;  and  these  la- 
minae, after  surrounding  the  stomach,  come  in  contact 
with  each  other  near  its  great  curvature.  From  this  portion 
of  the  stomach,  from  the  commencement  of  the  duode- 
num, and  also  from  the  spleen,  the  Omentum , composed 
of  two  laminae,  descends  over  the  colon  and  the  small  in- 
testines more  or  less  low  into  the  abdomen;  it  is  then 
folded  backwards  and  upwards,  and  is  continued  until  it 
meets  the  great  arch  of  the  colon:  here  the  laminae  again 
separate  and  inclose  that  portion  of  the  intestine,  on  the 
posterior  side  of  which  they  again  approach  each  other, 
and  form  a membrane  like  the  mesentery,  of  two  laminae, 
which  passes  from  the  concave  or  posterior  surface  of  the 
colon  to  the  back  of  the  abdomen,  where  it  is  continued 
into  the  membrane  which  lines  that  surface.  This  last  por- 
tion is  the  Mesocolon:  the  portion  between  the  liver  and 
stomach  is  called  the  Omentum  of  Winslow , or  the  lesser 
omentum;  and  the  great  portion  between  the  stomach  and 
colon  is  called  the  Great  Omentum , or  the  omentum  gastro 
colicum.  There  is  also  a process  of  peritoneum  continued 
from  that  portion  of  the  colon  which  is  on  the  right  side 
of  the  abdomen,  and  from  the  caecum,  which  extends  to 
some  distance;  it  is  formed  of  two  laminae,  that  compose 
a cavity  of  an  angular  form.  This  has  been  called  the 
Omentum  Colicum. 

The  great  and  small  omentum,  with  a portion  of  the 
peritoneum  on  the  back  of  the  abdomen,  form  a sac,  which 
incloses  a distinct  cavity  in  the  abdomen.  The  anterior 
part  of  this  sac  is  composed  of  two  laminae,  and  between 
these  laminae  are  the  stomach  and  the  great  arch  of  the 
colon.  This  cavity,  formed  by  the  two  omenta,  communi- 
cates with  the  general  cavity  of  the  abdomen  by  a foramen 


128  Varieties  in  the  Appearance  of  the  Omentum. 

of  a semicircular  form,  which  is  behind  the  great  cord  of 
the  vessels  that  go  to  the  liver. 

The  omentum  is  so  delicate  in  structure,  that,  when 
free  from  fat,  it  is  very  liable  to  laceration  merely  by  ad- 
hering to  the  fingers,  if  they  are  dry.  Winslow  therefore 
advised  that  some  unctuous  substance  should  be  rubbed 
on  the  hands,  before  they  were  applied  to  it. 

The  appearance  of  the  great  omentum  is  very  different 
in  different  persons.  In  the  emaciated,  it  appears  like  a 
delicate  transparent  membrane;  in  the  corpulent,  it  is  like 
a broad  mass  of  adeps,  which  sometimes  is  very  thick. 
When  it  is  thus  loaded  with  adeps,  it  is  most  commonly 
spread  over  the  small  intestines:  when  it  is  free  from  fat, 
it  is  often  compressed  together,  so  as  to  form  a small 
mass  near  the  arch  of  the  colon,  on  the  left  side. 

The  principal  bloodvessels  of  the  omentum  are  derived 
from  those  of  the  stomach,  and  are  called  gastro  epiploic 
arteries  and  veins. 

The  use  of  this  membrane  in  the  animal  economy  has 
not  been  ascertained  with  certainty.  It  seems  probable 
that  one  of  its-  principal  objects  is  to  protect  the  small 
intestines,  and  lessen  the  friction  consequent  upon  their 
motion;  but  it  has  been  supposed  to  answer  several  other 
important  purposes.* 

* See  Halleri  Elementa  Physiologia:,  vol.  VI.  pag:  381. 

Cavard.  Traite  de  Splanchnologie,  page  350. 

Dr.  James  Rush’s  Inquiry  into  the  use  of  the  Omentum. 


129 


CHAPTER  III. 

t)F  THE  LIVER,  THE  PANCREAS,  AND  THE  SPLEEN 

SECTION  I. 

Of  the  Liver. 

This  largest  viscus  of  the  abdomen,  when  in  a healthy 
condition,  is  of  a reddish  brown  color.  If  it  is  taken  out  of 
the  subject,  and  laid  on  a flat  surface,  it  is  flat,  but  in  the 
abdomen  it  is  convex  and  concave. 

It  is  situated  in  the  right  hypochondriac  region,  which  it 
occupies  entirely;  and  it  extends  through  the  upper  portion, 
of  the  epigastric  into  the  left  hypochondriac  region.  Being 
placed  immediately  under  the  diaphragm,  and  in  close 
contact  with  it,  as  well  as  with  the  inner  surface  of  the 
right  hypochondriac  region,  it  partakes  of  their  form,  and 
is  convex  above  and  concave  below.  When  thus  situated, 
it  is  of  an  irregular  figure,  between  the  circle  and  the  oval, 
but  it  is  broader  at  the  right  extremity  than  at  the  left,  and 
very  irregular  in  thickness.  The  edge  or  margin  which 
is  in  contact  with  the  posterior  part  of  the  right  hypochon- 
driac region,  is  very  thick.  It  gradually  becomes  thinner 
towards  the  left,  and  also  towards  the  front;  so  that  the 
right  margin,  and  a large  portion  of  the  posterior  margin, 
is  very  thick,  while  the  left  and  the  anterior  margin  is 
thin. 

The  upper  convex  surface  of  the  liver,  when  in  its  na* 
tural  situation,  is  smooth:  the  lower  concave  surface  is 
marked  by  several  grooves  or  fissures  and  eminences. 
One  of  these,  called  the  Umbilical  or  the  great  fissure,  com- 
Vol.  II.  R 


130 


Lobes  and  Fissures  of  the  Liver. 

mences  at  a notch  in  the  anterior  edge  of  the  liver,  to  the 
left  of  the  middle,  and  continues  to  the  posterior  edge.  At 
the  commencement  of  this  fissure  the  umbilical  ligament 
enters;  and  at  the  termination,  or  near  it,  the  vena  cava  is 
situated.  Opposite  to  this  fissure,  on  the  upper  or  convex 
surface,  is  a ligament  passing  from  the  diaphragm  to  the 
liver,  which  is  called  the  falciform.  The  fissure  and  the  li- 
gament divide  the  liver  into  its  two  great  lobes,  the  Right 
and  Left. 

Another  great  fissure,  called  the  transverse  or  principal , 
commences  in  the  right  lobe  and  extends  to  the  left,  cross- 
ing the  first  mentioned  fissure  at  right  angles,  and  extend- 
ing a very  short  distance  beyond  it.  It  is  very  deep,  and 
rather  nearer  to  the  posterior  than  the  anterior  edge  of  the 
liver.  In  this  fissure,  near  to  its  right  extremity,  the  great 
vein,  called  vena  portarum,  and  the  hepatic  artery  enter, 
and  the  excretory  duct  of  the  liver,  commonly  called  the 
hepatic  duct,  comes  out.  About  the  middle  of  the  fissure 
are  two  prominences,  one  on  each  side;  these  were  called 
the  portae,  or  gates  of  the  liver,  and  hence  the  great  vein 
was  called  vena  portarum.  This  vein  has  two  very  large 
rectangular  branches,  which  constitute  what  is  called  the 
sinus  of  the  vena  portarum,  and  they  occupy  the  principal, 
extent  of  the  fissure. 

The  liver  is  in  close  contact  with  the  vena  cava  behind; 
and  there  is  either  a groove  in  it  for  the  passage  of  the 
vein,  or  this  great  vessel  is  completely  inclosed  by  it. 
There  is  also  an  excavation  on  the  lower  surface  of  the 
liver,  which  is  occupied  by  a portion  of  the  gall  bladder. 

Besides  the  great  lobes  above  mentioned,  there  are 
also  two  or  three  prominent  parts  on  the  concave  surface, 
which  are  denominated  lobes.  One  of  these,  called  Lobulus 
Spigelii,  is  oblong,  with  two  sides,  and  an  angle  continued 


131 


Ligaments  of  the  Liv£r. 

along  its  whole  length,  which  extends  from  the  transverse 
fissure  to  the  posterior  margin  of  the  liver.  It  is  situated 
between  the  posterior  part  of  the  transverse  fissure,  or 
ductus  venosus,  and  the  vena  cava. 

The  anterior  extremity  of  this  lobe,  which  forms  one 
of  the  margins  of  the  transverse  fissure,  is  somewhat  bi- 
furcated, and  has  been  called  lobulus  caudatus.  The  largest 
portion  of  the  bifurcated  end  forms  a process  like  a papilla. 

Between  the  umbilical  fissure  and  the  depression  for  the 
gall  bladder  is  a protuberant  space,  which  varies  from  an 
inch  and  a quarter  to  two  inches  in  breadth.  This  has  also 
been  called  a lobe,  Lobulus  Quartus  or  Anonymus. 

The  peritoneum  is  extended  from  the  surface  of  the 
abdomen  to  the  surface  of  the  liver,  in  such  manner  as  to 
cover  it,  and  to  form  ligaments,  which  have  a great  effect 
in  retaining  it  in  its  proper  situation.  The  whole  posterior 
edge  of  the  liver  is  in  contact  with  the  back  of  the  abdo- 
men. The  peritoneum  above  the  liver  is  reflected  to  the 
upper  surface  of  it,  and  the  peritoneum  below  it  to  the 
lower  surface;  so  that  two  laminae  of  the  peritoneum  pass 
from  the  lower  part  of  the  diaphragm  at  the  back  of  the 
abdomen  to  the  posterior  edge  of  the  liver.  These  processes 
of  the  peritoneum  are  considered  as  forming  two  ligaments, 
which  are  called  the  right  and  left  lateral  ligaments.  A 
portion  of  the  posterior  surface  of  the  liver,  uncovered  by 
the  peritoneum,  is  often  in  contact  with  a portion  of  the 
tendon  of  the  diaphragm,  also  uncovered  by  pertoneum: 
around  this  place  of  contact,  the  peritoneum  is  extended 
from  the  diaphragm  to  the  liver,  and  thus  forms  what  has 
been  called  the  coronary  ligament  of  the  liver. 

The  peritoneum  of  the  right  side  of  the  diaphragm,  and 
of  the  abdominal  muscles,  as  far  down  as  the  umbilicus, 
is  extended  to  the  liver,  and  joins  it  on  the  convex  sur-> 


132  Mode  of  supporting  the  Liver. 

face  immediately  opposite  to  the  umbilical  fissure.  The 
peritoneum  from  the  left  side  of  these  parts  does  the 
same;  and  as  these  reflections  of  the  peritoneum  are  con- 
tinued from  so  low  a part  as  the  umbilicus,  they  are  ex- 
tended not  only  to  the  convex  surface  of  the  liver,  but 
also  to  the  great  notch,  and  along  the  umbilical  fissure. 

From  the  umbilicus  proceeds  a round  cord-like  liga- 
ment, which  in  the  foetal  state  was  a vein,  that  passes  to 
the  great  fissure  of  the  liver,  and  along  it.  The  process  of 
the  peritoneum  above  mentioned  is  so  conitected  with  this 
cord,  that  it  incloses  it  in  its  lower  edge,  and  the  whole  is 
called  the  falciform  ligament  of  the  liver.  The  cord,  when 
named  separately,  is  the  umbilical  or  the  round  ligament; 
and  the  membrane  or  laminae  of  the  peritoneum  fornas  the 
suspensory  ligament.  Besides  these,  the  peritoneum  on  the 
lower  side  of  the  liver  is  so  arranged,  that  it  not  only  ex- 
tends to  the  stomach,  but  to  the  duodenum  and  the  colon. 

By  these  ligaments  the  position  of  the  liver  must  be 
fixed  to  a great  degree;  and  there  is  one  additional  connec- 
tion, which  must  have  a great  effect  in  retaining  it  in  its 
proper  situation.  The  vena  cava  receives  two  or  three 
great  veins  from  the  liver,  at  the  place  where  it  is  in  con- 
tact with  the  posterior  edge  of  that  viscus;  these  veins  of 
course  pass  directly  from  the  substance  of  the  liver  into 
the  cava,  and  connect  it  to  that  vessel.  As  the  cava  is  sup- 
ported by  the  heart,  and  also  by  the  diaphragm,  it  must 
afford  a considerable  support  to  the  liver. 

When  the  stomach  and  intestines  are  distended,  they 
must  also  contribute  in  a considerable  degree  to  the  sup- 
port of  the  liver. 

The  liver  has  a strong  tendency,  when  we  are  erect,  to 
change  its  situation;  and  some  considerable  support  is  ne- 
cessary to  counteract  this  tendency.  It  would  move  to  the 


Acini  of  the  Liver.  Proper  Coat  of  the  Liver.  13S 

right,  when  we  lie  on  the  right  side,  if  it  were  not  in  con- 
tact with  the  ribs;  and  it  inclines  to  the  left,  for  want  of 
such  support,  when  we  lie  on  the  left  side. 

It  has  been  computed,  that  the  liver  descends  about  two 
inches,  when  the  position  of  the  subject  is  changed  from 
the  horizontal  to  the  erect.  As  it  is  in  contact  with  the 
diaphragm,  it  is1  obvious  that  it  must  be  influenced  by  the 
motions  of  that  muscle,  and  that  it  must  descend  when  the 
diaphragm  contracts. 

The  liver  is  composed  of  a substance  which  has  some 
firmness  of  consistence,  although  it  is  yielding;  and  is  also 
somewhat  brittle  or  friable.*  When  cut  into,  the  sections 
of  many  tubes, or  vessels  of  different  diameters,  appear  on 
the  cut  surface.  When  the  texture  of  this  substance  is 
more  closely  examined,  it  appears  somewhat  granulated, 
or  composed  of  very  small  bodies,  w hich  were  called  acini 
by  the  anatomists  who  first  described  them.  The  whole 
substance  is  inclosed  by  the  peritoneum,  which  is  ex- 
tended to  it  from  the  surface  of  the  abdomen  in  the 
manner  that  has  been  already  described.  It  has  also  a 
proper  coat  or  capsule;  and  on  the  posterior  edge,  where 
the  laminae  of  the  lateral  ligaments  pass  from  the  dia- 
phragm to  the  liver,  at  some  distance  from  each  other,  a 
portion  of  the  liver,  covered  by  this  coat  and  by  cellular 
substance,  is  in  contact  with  the  diaphragm.  The  same 
thing  occurs  likewise  at  the  coronary  ligament.f 

The  liver  holds  the  first  place  among  the  glands  of  the 

* It  lias  been  fractured  in  llie  living  body  by  external  violence. 

f Many  anatomists  deny  the  existence  of  this  coat;  but  if  one  of  the 
laminae  of  the  ligaments  be  carefully  peeled  off  from  the  surface  of  a 
liver  which  is  slightly  affected  by  putrefaction,  it  will  be  apparent,  al. 
though  very  thin.  It  was  described  by  M.  Laennec,  m Le  Journal  de 
Medecine  for  1803. 


134  Vessels  of  the  Liver.  Hepatic  Artery. 

body  for  size,  but  it  is  still  more  remarkable  for  some 
other  circumstances  in  its  economy.  In  addition  to  an  ar- 
tery, which  passes  to  it  as  arteries  do  to  other  glands, 
there  is  a large  vein  which  also  enters  it  as  an  artery;  and 
after  ramifying  throughout  the  liver,  communicates,  as 
does  the  artery,  with  other  veins,  which  carry  the  blood 
from  this  gland  into  the  vena  cava  and  the  general  circu- 
lation. There  are  therefore  three  species  of  bloodvessels 
in  the  liver;  and  with  these  are  found  the  vessels  which 
carry  out  of  the  gland  the  fluid  secreted  by  it,  or  the  bile. 

The  artery  of  the  liver  is  denominated  the  Hepatic  Ar- 
tery. The  vein  which  goes  to  the  liver  is  called  the  Vena 
Portarum , from  the  place  at  which  it  enters.  The  veins 
which  carry  to  the  vena  cava  the  blood  brought  to  the  li- 
ver by  the  hepatic  artery  and  the  vena  portarum,  are  called 
the  Hepatic  Veins;  and  the  duct  through  which  the  bile 
flow's  out  of  the  liver,  is  called  the  Hepatic  Duct.  Three 
of  these  vessels,  the  Hepatic  Artery , the  Vena  Portarum , 
and  the  Hepatic  Duct , enter  the  liver  at  the  great  fissure, 
at  the  spot  where  the  prominences  exist  called  the  portae; 
hence  the  name  vena  portarum  was  applied  to  the  vein. 

These  vessels  ramify  in  the  manner  presently  to  be 
described;  and  it  is  ascertained  by  minute  anatomical  in- 
vestigation, that  the  liver  is  entirely  composed  of  the  ra- 
mifications of  these  vessels  and  of  the  hepatic  veins,  with 
absorbent  vessels  and  nerves,  which  are  connected  toge- 
ther by  cellular  membrane. 

It  has  been  already  observed,  that  the  first  great  branch 
sent  off  by  the  aorta  in  the  abdomen,  the  Cceliac , divides 
into  three  branches,  which  go  respectively  to  the  stomach, 
the  liver,  and  the  spleen. 

The  Hepatic  is  generally  the  largest  of  these  branches. 
Tn  its  progress  t-ow'ards  the  liver  it  sends  off  an  artery  to 


Vena  Portarum. 


135 


the  stomach,  called  the  gastrica  dextra.  At  the  great  fis- 
sure it  divides  into  two  branches:  the  right  branch,  which 
supplies  the  right  lobe  of  the  liver,  is  of  course  the  largest. 
This  branch  sends  off  one  to  the  gall  bladder,  which  is  called 
the  cystic  artery;  and  also  some  smaller  branches:  it  passes 
under  the  hepatic  duct,  and  ramifies  through  the  great  lobe 
of  the  liver.  The  left  branch  is  distributed  through  the  left 
lobe  of  the  viscus.  It  can  be  proved  by  injection,  that  the 
hepatic  artery  communicates  not  only  with  the  hepatic 
veins,  but  with  the  biliary  duct,  and  the  vena  portarum 
also.  It  has  been  disputed  whether  the  size  of  this  artery 
is  greater  than  would  be  requisite  for  the  nourishment  and 
animation  of  the  liver. 

The  Vena  Portarum , the  great  peculiarity  of  the  liver, 
originates  from  all  the  chylopoietic  viscera  except  the  li- 
ver, and  is  of  course  formed  by  the  union  of  the  veins 
which  correspond  to  all  the  branches  of  the  cceliac  and 
mesenteric  arteries,  as  they  are  distributed  to  the  stomach 
and  intestines,  the  spleen,  the  pancreas,  and  the  omentum. 
The  veins  from  the  intestines  generally  form  two  great 
trunks,  which  are  denominated  the  greater  and  lesser  me- 
senteric veins.  The  great  mesenteric  vein  is  situated  to 
the  right,  and  rather  before  the  mesenteric  artery.  After 
it  has  approached  the  origin  of  the  artery,  it  separates 
from  it,  and  passes  behind  the  pancreas:  at  this  place, 
nearly  in  front  of  the  spine,  it  is  joined  by  the  great  vein 
of  the  spleen,  which  forms  almost  a right  angle  with  it, 
and  these  constitute  the  great  trunk  of  the  vena  portarum.. 
The  lesser  mesenteric  vein,  which  corresponds  to  the  in- 
ferior mesenteric  artery,  and  brings  blood  from  the  pelvis 
and  from  the  left  part  of  the  colon,  becomes  finally  a large 
vessel,  and  commonly  unites  with  the  splenic  about  an  inch 
and  a hajf  before  its  juhction  with  the  superior  mesenteric: 


136 


Hepatic  Duct. 

vein.  The  vena  portarum,  thus  formed,  proceeds  towards 
the  liver,  inclining  to  the  right,  and  is  generally  about 
three  inches  in  length:  in  its  course  it  sometimes  receives 
small  veins,  which  in  other  cases  pass  to  its  splenic  and 
mesenteric  branches.  When  it  has  arrived  at  the  great 
transverse  sinus  of  the  liver,  it  divides  into  two  large 
tranches,  each  of  which  forms  nearly  a right  angle  with 
it.  Their  size  is  so  great,  that,  when  distended  with  in- 
jection, they  appear  like  an  independent  vessel,  into  which 
the  vena  portarum  enters;  and  on  this  account  they  are 
called  the  great  Sinus  of  the  vena  portarum.  They  do  not 
adhere  firmly  to  the  glandular  substance  of  the  liver,  but 
are  united  to  it  by  cellular  membrane.  The  right  branch 
is  the  widest  and  shortest.  It  generally  divides  into  three 
branches;  an  anterior,  a posterior,  and  a lateral  branch; 
which  ramify  minutely,  and  extend  themselves  in  the  right 
lobe.  The  left  branch  is  much  longer,  and  continues  to  the 
extent  of  the  great  fissure.  Near  its  termination  it  is  join- 
ed by  the  umbilical  ligament,  which  has  been  already 
mentioned.  This  branch  is  generally  in  contact  with  a 
branch  of  the  hepatic  artery  and  of  the  hepatic  duct;  and 
ramifies,  like  the  right  branch,  into  the  contiguous  parts  of 
the  liver. 

The  Hepatic  or  excretory  duct  originates,  by  very  small 
vessels,  from  the  acini  or  corpuscles  of  which  the  liver  is 
composed,  and  into  which  the  minute  ramifications  of 
the  vena  portarum  and  hepatic  artery  extend.  They  ac- 
company these  vessels,  increasing  as  they  increase,  al- 
though the  fluid  they  contain  moves  in  an  opposite  direc- 
tion; and  two  large  branches  which  they  ultimately  form 
are  situated  at  the  portse  of  the  liver,  in  contact  with 
the  great  branches  of  the  vena  portarum  and  the  hepatic 
artery. 


Hepatic  Veins.  Nerves  of  the  Liver . 137 

These  three  vessels  are  in  contact  with  each  other  before 
they  enter  the  liver.  The  biliary  duct  is  anterior,  the  vena 
portarum  posterior, and  the  artery  to  the  left  of  them.  They 
are  accompanied  by  nerves  and  lymphatic  vessels,  and  are 
surrounded  by  a considerable  quantity  of  cellular  substance, 
and  thus  arranged  are  partially  covered  with  peritoneum. 
The  cellular  substance  which  invests  them  continues  with 
them  into  the  liver,  and  is  more  particularly  connected 
with  the  vena  portarum.  It  is  called  Glisson's  Capsule , and 
was  supposed  to  have  some  contractile  power,  which  as- 
sisted the  circulation  of  the  vena  portarum;  but  that  idea 
is  now  altogether  abandoned.  The  hepatic  veins,  which 
receive  the  blood  of  the  hepatic  artery  and  the  vena  por- 
tarum, open  into  the  anterior  part  of  the  vena  cava,  where 
it  is  in  contact  with  the  liver.  Generally  there  are  three  of 
these  veins,  but  sometimes  there  are  only  two;  in  which 
case  one  of  them  is  formed  by  two  others,  which  unite 
immediately  before  they  open  into  the  vena  cava.  It  is  to 
be  observed,  that  the  various  branches  of  these  veins  do 
not  accompany  those  branches  of  the  vena  portarum  or  he- 
patic artery  to  W'hich  they  correspond,  but  form  very 
large  angles  with  them.  This  is  probably  owing  merely  to 
their  termination  in  a part  so  distant  from  that  in  which 
the  artery  and  the  vena  portarum  originate;  but  it  is  very 
different  from  what  occurs  in  other  glands. 

The  Nerves  of  the  Liver  are  derived  from  the  semilu- 
nar ganglions  of  the  splanchnic  nerves.  From  these  many 
nerves  proceed,  which  form  a network  denominated  the 
solar  plexus.  From  this  plexus  many  threads  are  sent  off, 
which  form  a network  that  is  divided  into  the  right  and 
left  hepatic  plexus.  These  plexuses  surround  the  hepatic 
artery  and  the  vena  portarum,  and  accompany  them  in  their 
ramifications  throughout  the  liver,  being  inclosed  by  Glis- 
Vol.  II.  S 


138  Lymphatics.  Glandular  Substance  of  the  Liver. 

son’s  capsule.  They  receive  some  threads  from  the  sto- 
machic plexus,  formed  by  the  par  vagum.  Although  the 
number  of  nervous  fibres  is  very  considerable,  their  bulk, 
compared  with  that  of  the  liver,  is  very  small. 

The  Lymphatics  of  the  Liver  are  extremely  numerous; 
and  those  in  that  portion  of  the  peritoneum  which  invests 
the  liver  may  easily  be  rendered  conspicuous:  for  by 
pressure  the  injected  fluid  can  be  forced  from  the  trunks 
and  large  branches  into  the  small  ramifications,  in  opposi- 
tion to  the  valves.  When  all  the  surface  is  injected  in  this 
manner,  it  has  the  color  of  the  substance  injected;  as  is  the 
case  with  parts  which  are  very  vascular,  when  the  blood- 
vessels are  injected. 

The  deep-seated  lymphatics  are  also  very  numerous  in 
the  liver,  and  communicate  freely  with  the  superficial. 

The  superficial  lymphatics  which  are  on  the  upper  sur- 
face, proceed  through  the  diaphragm  into  the  thorax  in 
their  course  to  the  thoracic  duct.  Those  which  are  deep 
seated  emerge  from  the  liver  at  the  portae,  where  the  great 
vessels  enter,  and  unite  with  the  thoracic  duct  in  the  abdo- 
men, after  passing  through  several  glands.  The  lymphatics 
of  the  lower  surface  unite  with  the  deep-seated. 

The  glandular  or  parenchymatous  substance  of  the  liver 
is  of  a reddish  brown  color,  and  moderately  firm  consis- 
tence. When  it  is  cut  into,  the  cut  surface  exhibits  the 
sections  of  the  branches  of  the  different  bloodvessels 
above-mentioned,  and  of  the  excretory  ducts.  These  ves- 
sels are  often  distinguishable  from  each  other.  The  section 
of  the  biliary  duct  appears  the  thickest;  that  of  the  artery 
next;  the  vena  portarum  is  next  in  order;  and,  last  of  all, 
the  venae  hepaticse. 

The  branches  of  the  vena  portarum  are  surrounded  by 
cellular  substance,  or  Glisson’s  capsule;  and  therefore  ad- 


Peculiarity  of  the  Liver.  139 

here  less  to  the  substance  of  the  liver  than  the  branches  of 
the  hepatic  veins.  The  sections  of  the  hepatic  ducts  have 
often  bile  in  them,  and  are  therefore  termed  pori  biliarii. 
The  branches  of  the  artery  are  also  very  distinguishable. 

When  the  internal  substance  of  the  liver  is  brought  into 
view,  and  examined  accurately,  it  appears  to  be  formed 
of  small  bodies,  or  acini,  which  are  distinguishable  from 
each  other.  If  the  liver  happens  to  be  torn  or  lacerated, 
the  lacerated  surfaces  are  rough  and  irregular,  owing  to 
the^separation  of  these  acini  from  each  other. 

It  is  asserted  by  several  microscopical  observers,  that  a 
minute  branch  of  each  of  the  aforesaid  vessels  can  be 
traced  into  each  of  the  acini.  It  is  also  declared,  that  if 
each  of  these  vessels  be  injected  separately  with  mercury, 
oil  of  turpentine  colored,  or  a saturated  aqueous  solution 
of  gutta  gamba,  there  is  no  part  of  the  glandular  mass  as 
large  as  a grain  of  mustard  seed  in  which  these  vessels  will 
not  be  found. 

Several  anatomists  of  the  first  character  have  likewise 
declared,  that  a fluid  properly  injected  into  one  of  these 
vessels,  will  occasionally  pass  into  all  of  them.  Thus  an 
injection  will  not  only  pass  from  the  vena  portarum  to  the 
biliary  duct,  but  to  the  hepatic  artery  and  veins  also.  It 
will  likewise  pass,  in  a retrograde  course,  from  the  biliary 
ducts  to  the  vena  portarum,  and  to  the  hepatic  artery  and 
the  hepatic  veins;  or  from  any  one  of  the  four  orders  of 
vessels  into  the  three  others. 

The  great  peculiarity  of  the  liver  is,  that  venous  blood, 
instead  of  arterial,  is  brought  to  it  for  the  purpose  of  se- 
cretion. Thus,  the  great  vein  of  the  chylopoietic  viscera, 
instead  of  passing  to  the  cava,  enters  the  liver  by  the 
transverse  fissure,  and  takes  on  the  office  of  an  artery;  its 


140 


Gall  Bladder  and  Duct. 


coats,  on  this  account,  being  much  thicker  and  stronger 
than  those  of  the  hepatic  veins.* 

The  Biliary  or  Hepatic  Duct  is  formed  of  very  mi- 
nute vessels,  which  originate  in  the  acini  above  described; 
these  unite  together  like  veins  until  they  form  considera- 
ble branches,  which  finally  compose  the  great  ramifications 
of  the  biliary  duct.  This  duct  is  very  strong  and  firm,  and 
on  its  internal  surface  are  the  orifices  of  many  mucous 
follicles  or  ducts.  It  passes  from  the  transverse  fissure 
of  the  liver,  with  the  hepatic  artery,  as  before  described, 
and,  at  the  distance  of  an  inch  and  a half  or  two  inches 
from  the  fissure,  it  unites  with  a duct  from  the  gall  blad- 
der, which  is  called  the  Cystic  Duct.  This  duct  is  nearly 
equal  in  length  to  the  hepatic,  and  after  running  almost 
parallel  to  it,  at  length  unites  so  as  to  form  an  acute  angle 
with  it.  The  cystic  duct  is  smaller  than  the  hepatic,  and 
they  unite  much  like  two  branches  of  an  artery. 

The  Gall  Bladder , from  which  the  cystic  duct  arises,  has 
the  shape  of  a pear,  with  a very  long  neck,  curved  in  a way 
to  be  hereafter  described.  It  is  situated  in  a superficial  pit 
or  cavity  in  the  concave  surface  of  the  right  lobe  of  the 
liver;  and  its  fundus,  or  basis,  often  projects  a small  dis- 
tance beyond  the  anterior  edge  of  the  viscus.  Its  position 
is  such,  that  it  extends  from  before  backwards,  and  in- 
clines rather  to  the  left;  of  course,  therefore,  when  the 
subject  lies  on  his  back,  the  bottom  of  the  bladder  is  the 
uppermost  part  of  it;  when  he  lies  on  the  left  side,  it  is 

* A case  is  related  by  Mr.  Abernethy,  in  the  London  Philosophical 
Transactions,  in  which  the  vena  portarum  terminated  in  the  vena  cava 
below  the  liver,  without  communicating  with  it.  The  hepatic  artery 
was  the  only  vessel  which  carried  blood  to  the  organ,  and  was  un- 
usually large;  the  liver  being  nearly  of  the  natural  size.  Some  bile  was 
in  the  gall  bladder,  but  it  was  less  acrid  than  usual. 


Gall  Bladder.  3 4 X 

also  higher  than  the.  neck;  and  when  he  lies  on  the  right 
side,  it  is  the  lowermost. 

The  gall  bladder  consists  of  an  internal  coat,  and  one 
that  is  cellular  or  nervous,  and  has  somewhat  of  a fibrous 
appearance.  This  coat  connects  the  gall  bladder  to  the 
surface  of  the  pit  or  cavity  in  which  it  lies.  The  peritoneal 
coat  of  the  liver  is  extended  from  the  surface  of  the  viscus 
over  that  part  of  the  surface  of  the  gall  bladder  which  is 
not  in  contact  with  it. 

The  internal  coat  has  a peculiar  structure,  with  a faint 
resemblance  to  that  of  the  villous  membrane.  It  is  so  ar- 
ranged as  to  form  very  fine  folds,  which  have  various 
directions:  in  some  places  they  make  a network;  in  others, 
as  the  neck  of  the  bladder,  they  are  longitudinal.  Many 
mucous  follicles  exist  on  its  internal  surface. 

The  neck  of  the  gall  bladder  is  suddenly  bent  down  or 
curved  upon  itself,  and  twisted,  so  that  it  resembles  the 
neck  of  the  swan,  when  the  head  of  that  bird  is  applied  to 
one  side  of  its  breast. 

A branch  of  the  hepatic  artery,  which  leaves  it  before 
it  enters  the  liver,  is  appropriated  to  the  gall  bladder,  and  is 
therefore  denominated  the  cystic  artery.  The  veins  corres- 
ponding to  this  artery  empty  themselves  into  the  vena  por- 
tarum  * The  lymphatic  vessels  are  united  to  those  which 
are  found  on  the  lower  surface  of  the  liver,  and  the  nerves 
are  derived  from  the  hepatic  plexus. 

The  gall  bladder  appears  to  be  merely  a reservoir,  into 
which  bile  passes  through  its  duct  in  a retrograde  direc- 
tion. If  air  be  blown  through  the  hepatic  duct  from  the 
liver,  it  will  pass  to  the  gall  bladder  almost  as  freely  as  it 
passes  to  the  duodenum. 

* It  has  been  justly  observed  by  John  ^ell,  that  the  veins  would  npt 
terminate  thus,  if  bile  were  secreted  by  the  gall  bladder. 


142  Ductus  Communis  Choledochus.  ’'The  Bile . 

The  biliaiy  duct  from  the  liver,  after  receiving  the  duct 
from  the  gall  bladder,  takes  the  name  of  Ductus  Communis 
Choledochus.  It  is  wider  than  either  of  the  other  ducts,  and 
near  three  inches  in  length.  It  passes  down  before  the  vena 
portarum,  and  on  the  right  of  the  hepatic  artery,  to  the  pps- 
terior  surface  of  the  right  extremity  of  the  pancreas.  It 
passes  through  a small  portion  of  that  gland,  and  then  per- 
forates the  muscular  coat  of  the  duodenum;  after  which  it 
proceeds  from  half  an  inch  to  an  inch  between  this  coat 
and  the  villous,  and  opens  into  the  cavity  of  the  intestine. 
The  orifice  forms  a tubercle  which  extends  lengthways  of 
the  intestine,  and  is  rounded  above  and  pointed  below, 
with  a slit  in  it.  While  this  duct  is  in  contact  with  the 
pancreas,  a duct  from  that  gland  generally  opens  into  it, 
so  that  the  biliary  and  pancreatic  fluids  enter  the  duode- 
num by  the  same  orifice;  but  sometimes  the  pancreatic 
duct  opens  into  the  duodenum  by  a distinct  orifice,  very 
near  to  that  of  the  biliary  duct. 

The  Bile , or  fluid  secreted  by  the  liver,  appears  to  answer 
a two-fold  purpose  in  the  animal  economy.  It  produces 
a chemical  effect  upon  the  alimentary  mixture  which 
passes  from  the  stomach  through  the  intestines;  and  it 
increases  the  peristaltic  motion  of  those  important 
organs. 

By  an  inverted  action  of  the  duodenum,  some  of  this 
fluid  is  frequently  carried  upwards  into  the  stomach:  it 
then  often  produces  only  slight  derangement  of  the 
functions  and  sensations  connected  with  that  viscus;  but 
sometimes  violent  vertigo , and  even  convulsions , seem 
to  have  arisen  merely  from  the  presence  of  a large 
quantity  of  bile  in  the  stomach;  for  they  have  gone  off 
completely  upon  the  discharge  of  bile  by  vomiting. 

Notwithstanding  these  effects  of  bile  in  certain  cases, 


The  Bile. 


143 


in  which  a great  deal  of  it  exists  in  the  stomach,  it  is 
often  carried  into  the  mass  of  blood  in  large  quantities, 
and  appears  to  be  mixed  with  the  serum,  and  to  circu- 
late through  the  body,  without  producing  any  very  sen- 
sible effect:  thus  many  persons  who  are  deeply  tinged 
by  bile  in  their  blood,  experience  but  few  effects  that 
can  be  imputed  to  the  mixture  of  it  with  the  circulating 
fluids;  and  neither  the  brain  nor  the  heart  appear  to  be 
much  influenced  by  the  circumstance. 

Bile  is  miscible  with  water  and  with  alcohol,  and  also 
with  oily  substances;  and  it  often  assumes  a green  co- 
lor, when  mixed  with  acids.  The  color  of  the  alvine 
discharges  is  derived  from  the  bile,  and  they  are  there- 
fore sometimes  very  green,  when  the  acetous  fermen- 
tation takes  place  in  the  contents  of  the  stomach  and 
bowels. 

It  is  asserted  by  some  chemists,  that  ten  parts  in 
eleven  of  the  human  bile  consist  of  water;  that  albu- 
minous matter  composes  about  one  forty-sixth  part  of 
it;  and  that  there  is  nearly  an  equal  quantity  of  resin- 
ous matter  in  it.  There  is  also  a small  quantity  (one 
part  in  244)  of  uncombined  soda  dissolved  in  it,  and  a 
smaller  quantity  of  neutral  salts,  consisting  of  soda 
combined  with  the  phosphoric,  sulphuric  and  muriatic 
acids.  In  addition  to  these  there  is  a very  small  quan- 
tity of  phosphate  of  lime  and  of  oxide  of  iron,  and  some 
yellow  insoluble  matter. 

The  bile  in  the  Gall  Bladder  is  generally  more  vis- 
cid than  that  which  is  found  in  the  Hepatic  Duct , 


144 


The  Pancreas. 


SECTION  II. 

Of  the  Pancreas. 

THE  pancreas  is  a glandular  body,  which  has  a strong 
resemblance  to  the  salivary  glands  in  several  particulars. 
It  is  nearly  six  inches  in  length,  and  is  irregularly  oblong  in 
its  form,  one  extremity  being  much  larger  than  the  other. 
Its  large  extremity  is  in  contact  with  the  duodenum,  and 
it  extends  from  this  intestine  in  a transverse  direction  to 
the  spleen,  to  which  it  is  connected  by  the  omentum  and 
by  bloodvessels.  It  is  not  invested  by  the  peritoneum,  but 
is  situated  in  the  space  which  exists  between  the  two  la- 
mina of  the  mesocolon,  as  they  proceed  from  the  back  of 
the  abdomen,  before  they  come  in  contact  with  each  other. 
It  is  anterior  to  the  aorta  and  vena  cava,  and  to  the  mesen- 
teric vein,  or  main  branch  of  the  vena  portarum;  being  con- 
nected to  these  parts  by  cellular  membrane.  At  the  right 
extremity,  which  is  connected  with  the  duodenum,  is  a 
process  of  the  gland  that  extends  downwards  in  close 
contact  with  the  intestine.  This  is  called  the  head  of  the 
pancreas,  or  the  lesser  pancreas. 

The  position  of  the  pancreas  is  such,  that  one  of  its  sur- 
faces looks  forwards  and  rather  upwards,  and  the  other 
backwards  and  downwards;  one  edge  is  of  course  poste- 
rior and  superior,  and  the  other  anterior  and  inferior.  The 
posterior  of  these  edges  is  much  thicker  than  the  other, 
and  has  a groove  or  excavation  which  is  occupied  by  the 
splenic  bloodvessels. 

This  gland  differs  from  the  other  large  glands  of  the 
abdomen,  inasmuch  as  it  has  not  a large  artery  particu- 
larly appropriated  to  it;  but  instead  of  this,  it  receives 
branches  from  the  contiguous  arteries. 


Pancreatic  Duct. 


145 


The  arterial  blood  of  this  gland  is  partly  supplied  by  the 
splenic  artery,  which,  in  its  course  from  the  main  trunk  of 
the  cceliac  to  the  spleen,  while  it  is  in  the  groove  at  the 
edge  of  the  pancreas,  sends  off  into  the  gland  one  consi- 
derable branch  called  the  great  pancreatic,  and  a num- 
ber of  small  branches,  which  go  off  in  succession.  In  ad- 
dition to  these,  the  pancreas  receives  vessels  from  one 
of  the  branches  of  the  hepatic  artery,  before  it  sends 
off  its  great  ramifications,  as  well  as  small  twigs  from  se- 
veral other  contiguous  arteries.  The  veins  correspond 
with  the  arteries,  but  ultimately  are  discharged  into  the 
vena  portarum. 

The  pancreas  resembles  the  salivary  glands  in  color,  and 
also  in  texture;  for  it  is  of  a dull  white  color  with  a tinge 
of  red,  and  it  appears  to  consist  of  small  bodies  of  a gra- 
nulated form,  which  are  so  arranged  as  to  compose  small 
masses  or  lobes  that  are  united  to  each  other  by  cellular 
membrane.  Each  of  these  granulated  bodies  receives  one 
or  more  small  arterial  twigs,  and  from  it  proceeds  not 
only  a vein  but  a small  excretory  duct,  which  uniting  with 
similar  ducts  from  the  adjoining  granulated  portions  or 
acini,  forms  a larger  duct  in  each  lobe  or  mass;  these  open 
into  the  great  duct  of  the  gland,  which  proceeds  through 
it  lengthwise  from  the  left  extremity,  in  which  it  com- 
mences, to  the  right. 

This  duct  is  situated  in  the  body  of  the  gland,  which 
must  be  dissected  to  bring  it  into  view.  It  is  thin  and 
transparent,  like  the  ducts  of  the  salivary  glands,  and  is 
rather  larger  in  diameter  than  a crow’s  quill.  In  its  pro- 
gress towards  the  right  extremity  of  the  gland  it  gradually 
enlarges,  and  commonly  receives  a branch  from  the  part 
called  the  lesser  pancreas.  It  most  commonly  unites  with 
the  biliary  duct  before  it  opens  into  the  duodenum:  some* 

Vol.  II.  T 


146 


Size  of  the  Spleen. 

times  these  ducts  open  separately,  but  very  near  to  each 
other.  They  penetrate  the  coats  of  the  intestine  rather 
obliquely,  and  between  four  and  five  inches  from  the  py- 
lorus. This  canal  is  sometimes  called  Ductus  Wirsungi , 
after  an  anatomist  who  published  a plate  of  it. 

The  pancreas  has  an  irregular  surface,  and  no  coat 
which  covers  it  uniformly.  It  is  invested  by  cellular  mem- 
brane, which  also  connects  its  different  lobes  to  each 
other.  Absorbent  vessels  and  nerves  are  traced  into  it. 

The  portion  called  the  lesser  pancreas  adheres  to  the 
duodenum,  and  when  it  is  enlarged  by  disease,  the  pas- 
sage of  aliment  through  that  intestine  is  much  impeded, 
and  sometimes  completely  obstructed.* 

It  is  now  generally  believed  that  the  fluid  secreted  by 
the  pancreas  is  similar  to  that  which  is  produced  by  the 
salivary  glands. 

SECTION  III. 

Of  the  Spleen. 

THE  Spleen  is  a flat  body  of  a blueish  color,  and  an 
irregular  oblong  form,  with  thick  edges,  which  are  indent- 
ed in  some  places. 

It  is  various,  in  different  subjects,  both  in  size  and 
form.  Its  most  common  size  is  between  four  and  five 
inches  in  length, and  about  three  or  four  inches  in  breadth; 
but  it  has  often  been  found  of  more  than  four  times  this 
size;  and  it  has  also  been  seen  not  much  longer  than  an 

* In  several  cases  where  examination  after  death  evinced  that  the 
pancreas  had  become  enlarged  and  indurated,  particularly  at  the  right, 
extremity,  the  principal  symptoms  w ere  jaundice;  great  uneasiness  after 
taking  food;  vomiting  some  time  after  eating,  but  not  immediately;  extreme 
acidity  of  the  matter  rejected. 


Enlargement  of  the  Spleen.-  147 

inch.  Its  ordinary  weight  is  between  six  and  nine  ounces; 
but  it  has  varied  in  different  subjects  from  eleven  pounds 
to  one  ounce.  It  is  supposed,  by  many  physiologists,  that 
it  frequently  varies  in  size  in  the  same  individual. 

It  is  situated  in  the  left  hypochondriac  region,  in  con- 
tact with  the  diaphragm,  below  the  eighth  rib.  The  posi- 
tion of  the  spleen  is  somewhat  oblique, — one  extremity 
being  directed  downwards  and  rather  forwards,  and  the 
other  upwards  and  backwards;  but  when  the  stomach  is 
distended,  the  lower  end  of  it  is  pushed  forward  by  the 
great  extremity  of  that  viscus. 

In  general  it  is  so  deeply  seated  in  the  left  hypochon- 
driac region,  that  it  is  out  of  view  when  the  subject  is  open- 
ed in  the  ordinary  way:  but  in  some  cases  of  enlargement, 
after  the  intermitting  fever,  it  has  extended  downwards, 
nearly  as  low  as  the  pelvis;  and  towards  the  right  side, 
beyond  the  umbilicus. 

The  external  surface  of  the  spleen  is  convex,  in  confor- 
mity to  the  surface  of  the  diaphragm,  with  which  it  is  in 
contact.  The  internal  surface  of  the  spleen  is  irregularly 
concave,  having  a longitudinal  fissure  which  divides  it 
into  two  portions. 

The  spleen  is  invested  by  the  peritoneum,  one  process 
of  which  is  often  extended  from  the  diaphragm,  above  and 
behind  it,  in  the  form  of  ligament.  Another  process  of  the 
same  membrane  is  extended  to  it  from  the  great  extremity 
of  the  stomach.  The  peritoneum  is  also  continued  from 
the  spleen  in  the  form  of  omentum. 

Within  this  peritoneal  covering  is  the  proper  coat  of  the 
spleen,  which  is  so  closely  connected  to  it,  that  many  ana- 
tomists have  considered  them  as  one  membrane:  they  are, 
however,  very  distinct  at  the  great  fissure,  but  the  exter- 
nal coat  is  extremely  thin. 


148 


Vessels  of  the  Spleen. 

The  proper  coat  of  the  spleen  is  not  very  thick;  it  is 
dense  and  firm,  and  somewhat  elastic,  but  not  much  so.  It 
is  partly  transparent. 

The  spleen  has  a large  artery,  which  is  one  of  the  three 
great  branches  of  the  coeliac.  This  vessel  runs  in  an  undu- 
lating manner  in  a groove  in  the  upper  edge  of  the  pan- 
creas, and  in  this  course  sends  off  many  small  branches  to 
supply  that  gland.  The  splenic  artery,  before  it  arrives  at 
the  spleen,  divides  into  five  or  six  branches,  which  are  also 
undulating  in  their  progress,  and  penetrate  into  the  body 
of  the  viscus  at  the  above-mentioned  fissure.  These 
branches  are  distributed  to  every  part  of  the  viscus,  and 
ramify  minutely. 

From  these  branches,  or  from  the  main  trunk  before  it 
ramifies,  three  or  four  smaller  branches  proceed  to  the  left 
extremity  of  the  stomach.  They  are  called  vasa  brevia  or 
arterise  breves. 

The  arteries  which  enter  the  spleen  are  accompanied 
by  veins  that  emerge  from  it,  and  unite  to  form  a great 
trunk.  This  trunk  observes  a course  corresponding  to  that 
of  the  splenic  artery,  and  receives  veins  from  the  stomach 
and  pancreas,  which  correspond  with  the  arterial  branches 
sent  to  those  organs.  The  splenic  vein  is  one  of  the  prin- 
cipal branches  of  the  vena  portarum. 

The  splenic  artery  is  very  large  in  proportion  to  the 
viscus  to  which  it  is  sent,  and  the  vein  is  unusually  large 
in  proportion  to  the  artery.  The  vein  is  also  very  tender 
and  delicate  in  its  structure. 

The  absorbent  vessels  of  the  spleen  are  very  numer- 
ous. It  has  been  asserted,  that  when  those  of  the  external 
coat  of  the  spleen  are  injected,  they  are  sufficient  to 
form  a fine  network  on  it.  The  absorbents  of  the  deep- 
seated  parts  unite  to  the  superficial  at  the  fissure  where 


Malpighi  on  the  Structure  of  the  Spleen.  149 

the  bloodvessels  enter.  They  terminate  in  the  thoracic 
duct,  after  passing  through  several  lymphatic  glands. 

The  nerves  of  the  spleen  are  derived  from  the  solar 
plexus:  they  form  a plexus  round  the  vessels,  and  accom- 
pany them  through  the  viscus. 

The  spleen  consists  of  a substance  which  is  much  softer 
than  that  of  any  other  viscus  of  the  abdomen.  This  sub- 
stance is  made  up  either  wholly  or  in  great  part  of  the 
ramifications  of  the  splenic  artery  and  vein,  which  are  de- 
monstrated by  injections  to  be  very  minute  and  numerous 
in  this  body.  There  are  also  many  fine  white  cords,  like 
threads,  which  pass  from  the  internal  surface  of  the  inner 
coat  of  the  spleen  into  its  soft  substance,  in  which  some 
of  them  ramify.  These  cords  connect  the  substance  of  the 
spleen  pretty  firmly  to  its  coat,  and  they  seem  to  have  the 
effect  of  rendering  the  exterior  part  of  the  substance  more 
firm  and  dense  than  the  internal.  They  are  particularly 
conspicuous  if  the  spleen  be  immersed  in  water,  and  the 
coat  pulled  off  while  it  is  in  that  situation. 

The  spleen  has  a strong  resemblance  to  the  glandular 
organs,  but  has  no  excretory  duct,  and  its  particular  func- 
tion is  not  very  obvious:  for  these  reasons  the  structure 
of  this  organ  is  a subject  of  very  interesting  inquiry. 

Malpighi,  who  took  the  lead  in  researches  of  this  nature, 
before  injections  of  the  bloodvessels  with  wax  were  in 
use,  after  investigating  the  structure  of  the  spleen  by 
long  maceration,  by  boiling,  by  inflation,  by  the  injection 
of  ink  or  colored  fluids,  and  by  examination  with  micro- 
scopes, declared  that  its  structure  was  cellular;  that  the 
cells  communicated  more  freely  with  the  veins  than  the 
arteries;  and  that  they  might  be  considered  as  appendices 
of  the  veins.  He  also  asserted,  that  a large  number  of 
white  bodies  or  vesicles  were  to  be  found  in  those  cells, 


150  Ruysch  on  the  Structure  of  the  Spleen. 

and  throughout  the  whole  substance  of  the  spleen,  which 
were  in  bunches  like  grapes,  and  preserved  their  whitish 
color  although  the  vessels  around  them  were  injected  with 
a colored  fluid.  This  description  of  Malpighi  appears  to 
have  been  admitted  by  some  of  the  very  respectable  ana- 
tomists who  were  cotemporary  with  him;  but  it  was  most 
zealously  opposed  by  Ruysch,  who  exhibited  the  spleen 
£0  completely  injected  with  wax,  that  it  appeared  to  be 
composed  entirely  of  vessels.* 

Ruysch  appears  to  have  paid  great  attention  to  this 
subject,  and  to  have  made  man)'  preparations  of  the 
spleen.  From  these  he  derived  the  opinion,  that  the  sub- 
stance of  this  organ  was  entirely  composed  of  arteries, 
veins,  absorbent  vessels  and  nerves;  and  that  if  it  were 
properly  injected  before  it  was  dissected,  no  other  struc- 
ture would  be  found.  He  stated,  that  the  minute  ramifica- 
tions of  the  bloodvessels  appeared  to  have  acquired  a 
peculiar  quality,  and  were  so  soft  and  delicate,  that  their 
texture  was  destroyed  by  the  least  friction;  and  that  by 
the  slightest  degree  of  putrefaction  they  appeared  to  be 
reduced  to  a fluid  state.  Fie  also  denied  the  existence  of 
cells,  or  of  the  whitish  bodies  described  by  Malpighi. 

The  question  thus  at  issue  between  these  great  masters 
of  their  art,  was  very  carefully  examined  by  M.  De  La 
Sone,  a French  physician,  whose  observations  are  publish- 
ed in  the  Memoirs  of  the  Academy  of  Sciences  for  1754. 
After  repeating  the  processes  of  each  of  these  anatomists, 
and  instituting  some  others  in  addition,  he  adopted  the 

* Two  plates,  taken  from  drawing's  of  these  preparations,  are  pub- 
lished in  Ruysch’s  works.  One  is  attached  to  Epistola  Problematica 
Quart  a,  in  the  second  volume;  and  the  other  to  Thesaurus  Septimus, 
in  tlie  third  volume. 


151 


De  La  Sone  on  the  Spleen. 

opinion  that  there  was  in  the  texture  of  the  spleen  a pulpy 
substance  which  was  not  a mere  coagulum,  but  which, 
however,  could  not  be  injected. 

He  derived  his  opinion  from  this  fact  among  others. 
After  macerating  the  spleen  a considerable  time,  and  inject- 
ing water  into  the  vessels  until  it  returned  colorless,  he  in- 
jected ink,  and  confined  it  some  time  in  the  vessels  by  tying 
them:  he  then  allowed  the  ink  to  flow  out  of  the  ves- 
sels, and  made  various  sections  of  the  spleen,  but  no  ink 
appeared  in  the  pulpy  substance,  although  it  was  visible  in 
many  small  vessels  which  ramified  in  that  substance.  He 
observes  that  this  could  not  have  been  the  case,  if  the 
pulpy  substance  had  been  composed  entirely  of  vessels, 
as  was  supposed  by  Ruysch. 

He  also  examined  the  spleen  after  it  had  been  injected 
with  wax,  according  to  the  manner  of  Ruysch,  and  be- 
lieved not  only  that  the  pulpy  matter  remained  uninject- 
ed, but  that  Ruysch  himself,  in  his  own  preparations,  re- 
moved this  substance,  supposing  it  to  exist  for  the  mere 
purpose  of  connecting  the  vessels  to  each  other. 

To  see  the  bloodvessels  in  the  same  state  of  distention 
in  which  they  were  during  life,  he  tied  the  splenic  vessels  in 
a living  animal,  and  removed  the  spleen  with  the  ligatures 
on  the  vessels.  In  this  situation  he  boiled  it,  and  then  ex- 
amined the  appearance  of  the  vessels  and  the  pulpy  sub- 
stance. From  these,  as  well  as  his  other  observations,  he 
decided,  that  the  pulpy  substance  did  not  consist  entirely 
of  vessels,  but  was  an  additional  and  different  structure. 

He  also  suggested,  that  as  the  brain  and  the  muscular 
fibres  were  so  covered  by  bloodvessels  in  the  injected  pre- 
parations of  Ruysch,  that  they  appeared  to  be  composed 
entirely  of  vessels,  when  in  fact  they  consisted  of  a differ- 


152  Haller  and  the  French  Anatomists  on  the  Spleeu. 

ent  substance,  so  the  pulpy  substance  of  the  spleen  was 
covered  or  obscured  by  the  bloodvessels  which  passed 
through  it,  without  constituting  its  whole  substance. 

He  confirms  the  account  of  Malpighi  respecting  the 
Whitish  Vesicles  or  Follicles;  and  states,  that  in  a majority 
of  cases  they  are  not  to  be  discovered  without  a particular 
preparation;  but  that  they  are  generally  made  obvious  by 
long  maceration  of  the  spleen  in  water.  In  his  opinion 
they  are  the  most  essential  part  of  the  organ. 

Notwithstanding  these  investigations 'of  M.  De  La 
Sone,  the  question  respecting  the  structure  of  the  spleen 
remains  not  completely  decided  even  to  this  day. 

Haller,  who  w’as  perfectly  well  acquainted  with  the 
subject,  inclined  to  the  opinion  of  Ruysch;  while  Sabatier 
adopted  completely  the  opinion  of  De  La  Sone. 

It  appears  from  the  statement  of  Gavard,  that  Desault 
did  not  admit  the  existence  of  the  transparent  bodies; 
although  he  believed  that  the  pulpy  substance  of  the 
spleen  consisted  of  cells  which  resembled  those  of  the 
cavernous  bodies  of  the  penis. 

Boyer,  whose  descriptions  of  the  animal  structure  ap- 
pear to  have  been  formed  with  scrupulous  exactitude, 
admits  the  existence  of  transparent  bodies;  sometimes  so 
small  as  to  be  scarcely  visible,  and  sometimes  as  large  as 
the  head  of  a pin.  He  observes,  that  the  best  method  of 
examining  them  is  to  place  a very  thin  slice  of  the  spleen 
between  the  eye  and  a strong  light,  when  the  transparency 
of  these  bodies  occasions  the  slice  of  the  spleen  to  appear 
as  if  perforated. 

As  to  the  general  structure  of  the  pulpy  substance,  he 
avows  himself  unable  to  decide  respecting  it;  but  ob- 
serves, that  upon  examining  the  cut  surface  of  the  spleen, 
you  perceive  black  liquid  blood  flow  from  the  vessels;  if 


153 


British  Anatomists  on  the  Spleen. 

you  then  scrape  this  surface,  you  may  express  easily  a 
species  of  sanies  different  from  that  which  flows  from  the 
vessels,  which,  after  exposure,  becomes  red,  and  resembles 
coagulated  blood:  whether  this  is  contained  in  the  capil- 
lary vessels,  or  in  the  cavities  of  this  organ,  he  acknow- 
ledges himself  unable  to  determine. 

Notwithstanding  the  sentiments  of  these  French  gen- 
tlemen, many  of  the  British  Anatomists,  who  are  entitled 
to  great  attention  on  account  of  their  skill  in  minute  in- 
jections, have  adopted  the  ideas  of  Ruysch.  Among  these 
are  to  be  mentioned  the  late  Dr.  F.  Nicholls,  and  many  of 
the  anatomists  of  London,  as  well  as  the  second  Professor 
Monro,  of  Edinburgh.  There  are,  however,  two  remark- 
able exceptions  to  this  account  of  the  British  Anatomists. 
The  late  Mr.  Falconar,  who  wrote  a dissertation  on  the 
situation  and  structure  of  the  spleen,  which  contains 
the  sentiments  of  the  late  truly  respectable  Mr.  Hew- 
son,*  after  stating  that  the  organ  was  extremely  vascular, 
so  that  when  injected  it  appeared  like  a mere  congeries  of 
vessels,  makes  this  unequivocal  assertion, — that  there  are 
innumerable  cells  dispersed  throughout  the  whole  sub- 
stance of  it,  which  are  so  small  that  they  are  only  to  be 
discovered  by  the  aid  of  a microscope ; and  are  to  be  seen 
after  steeping  a thin  piece  of  spleen,  the  bloodvessels  of 
which  have  been  minutely  injected,  in  clear  water  during 
a day,  and  changing  the  water  frequently.  He  also  adds., 
that  the  ultimate  branches  of  the  arteries  and  veins  form 
a beautiful  network  on  each  cell;  and  that  these  cells  are 
sufficiently  distinguished  from  the  irregular  interstices  of 
the  cellular  substance,  by  their  round  figure  and  their 
great  regularity. 


Voi.  IT 


See  Experimental  Inquiries,  ml.  III-,. 

u 


154 


Questions  relating  to  the 

Mr.  Everard  Home,  in  his  papers  on  the  structure  and 
uses  of  the  spleen,  confirms  the  account  of  the  vesicles  in 
this  organ;  and  adds,  that  these  vesicles  are  occasionally 
seen  in  a distended  and  in  a contracted  state.  That  when 
distended  they  are  twice  as  large  as  when  contracted,  and 
are  distinguishable  by  the  naked  eye;  whereas,  when  con- 
tracted, they  require  a magnifying  glass  to  be  distinctly 
seen.  These  observations  appear  to  have  been  made  upon 
quadrupeds.* 

Professor  Soemmering  appears  to  unite  in  the  general 
sentiment  of  the  British  anatomists,  that  the  spleen  is  sim- 
ply vascular.  He  says,  that  the  tuberculi  which  sometimes 
appear  in  it,  when  examined  with  a magnifying  glass,  ap- 
pear to  be  composed  entirely  of  vessels. 

There  are  therefore  two  questions  not  perfectly  decid- 
ed respecting  the  spleen. 

First.  Whether  its  general  structure  is  simply  vascular, 
or  whether  there  is  any  other  structure,  either  cellular  or 
more  substantial,  which  composes  its  general  bulk. 

Second.  Whether  the  small  transparent  vesicles,  ori- 
ginally described  by  Malpighi,  are  to  be  regarded  as  es- 
sential parts  of  the  structure  of  the  spleen. 

With  respect  to  the  first  question,  the  injections  of 
Ruysch,  and  of  the  British  Anatomists  in  general,  and 
even  of  Mr.  Hewson,  as  well  as  of  Haller  and  Soemmer- 
ing, seem  to  afford  positive  facts  in  opposition  to  those  of 
a negative  kind  adduced  by  M.  De  La  Sone,  and  render 
it  highly  probable  that  the  general  structure  is  simply 
vascular. 

But  the  second  question  stands  on  different  grounds. 
The  existence  of  small  transparent  vessicles,  although  de- 


* See  the  London  Philosophical  Transactions  for  1808. 


155 


Structure  of  the  Spleen. 

tried  by  Ruysch,  and  neglected  by  the  British  Anatomists  in 
general,  was  asserted  as  a positive  fact  by  Malpighi  and  De 
La  Sone;  and  their  assertions  have  been  confirmed,  not 
only  by  most  of  the  French  Anatpmists,  but  also  by  Hew- 
son  and  Home  among  the  British. 

The  sentiments  of  physiologists  respecting  the  func- 
tions of  the  spleen,  are  more  discordant  than  those  of 
anatomists  respecting  its  structure;  although  the  subject 
has  been  considered  by  many  authors  of  great  ingenuity.* 

* See  M.  Lieutaud.  Elementa  Physiologic. 

Hewson’s  Experimental  Inquiries,  vol.  III. 

Dr.  Rush.  Medical  Museum,  vol.  III. 

Haller.  Elementa  Physiologic,  tom.  vi.  pag.  414. 


156 


CHAPTER  VI. 

OF  THE  URINARY  ORGANS,  AND  THE  GLANDULE  RENALES 

The  urinary  organs  consist  of  the  Kidneys,  which  are 
situated  in  the  lumbar  regions;  of  the  Bladder,  which  is  in 
the  pelvis;  of  the  Ureters,  which  are  flexible  tubes  or  ca- 
nals that  pass  from  the  kidneys  to  the  bladder;  and  of  the 
Urethra , or  tube  through  which  the  urine  is  discharged 
from  the  bladder. 

These  organs  have  but  little  connection  with  the  peri- 
toneum. The  kidneys  are  behind  it;  and  a considerable 
quantity  of  cellular  membrane  is  placed  between  them  and 
it.  The  ureters  are  also  behind  it;  and  but  a part  of  the 
bladder  is  invested  with  it. 

The  Glandulce  Renales  are  described  with  the  urinary 
organs,  on  account  of  their  contiguity  to  the  kidneys;  and 
to  avoid  a derangement  of  the  natural  order  of  descrip- 
tion they  are  considered  first. 

The  urethra  pertains  to  the  organs  of  generation  as  well 
as  to  the  urinary  organs,  and  can  be  described  most  ad  van* 
tageously  with  them. 

SECTION  I. 

Of  the  Glandules  Renales. 

THESE  are  two  small  bodies,  situated  on  the  psoas 
muscle,  one  on  each  side  of  the  spine,  behind  the  peri- 
toneum and  above  the  kidney,  being  in  contact  with 
its  upper  and  anterior  edge.  They  have  an  irregular  se- 
milunar figure  with  three  sides,  one  of  which  is  accom- 


Glandules  Renales. 


157 


modated  to  the  Convexity  of  the  kidney.  Their  color  is 
commonly  a dull  yellow. 

The  appearance  and  texture  of  these  bodies  have  some 
resemblance  to  those  of  glands,  and  hence  their  name;  but 
they  have  no  excretory  duct. 

When  they  are  laid  open  by  an  incision,  a cavity  often 
appears,  which  is  somewhat  triangular,  and  from  the  lower 
part  of  it  a small  thin  ridge  arises.* 

A small  quantity  of  fluid  is  generally  found  in  it,  which 
has  a very  dark  color  in  adults,  is  yellowish  in  young  sub- 
jects, and  red  in  infants. 

These  bodies  have  not  a single  artery  appropriated  to 
them,  as  the  spleen  has,  but  receive  small  branches  from 
several  contiguous  sources;  viz.  from  the  arteries  of  the 
diaphragm,  from  the  cceliac  artery  or  the  aorta,  and  from 
the  arteries  of  the  kidneys.  There  is  generally  one  princi- 
pal vein,  as  well  as  some  that  are  smaller,  belonging  to 
each  of  these  bodies:  the  large  vein  on  the  right  side  ge- 
nerally opens  into  the  vena  cava,  and  on  the  left  into  the 
left  emulgent  vein. 

These  bodies  were  first  described  by  Eustachius,  and 
have  been  regarded  with  attention,  by  many  anatomists 
since  that  period.  They  exist  in  a great  number  of  animals; 
but  their  nature  and  functions  are  altogether  unknown. 

* The  cavity  in  these  bodies  has  sometimes  been  sought  for  in  vain. 
Haller  found  it  in  sixteen  cases  out  of  nineteen 


/ 


158 


SECTION  II. 

Of  the  Kidneys  and  Ureters. 

THE  kidneys  are  two  glandular  bodies  which  secrete 
the  urine.  They  are  of  a dull  red  color,  and  their  form 
has  a strong  resemblance  to  that  of  the  bean  which  bears 
their  name.  They  have  a peculiar  texture,  which  is  uni- 
form, and  not  granulated  or  composed  of  acini;  and  they 
are  covered  by  a thin  delicate  tunic,  which  has  no  connec- 
tion with  the  peritoneum. 

They  are  situated  in  the  lumbar  regions  of  the  abdo- 
men, one  on  each  side  of  the  spine.  They  are  opposite  to 
the  two  last  dorsal  and  the  two  first  lumbar  vertebra.  They 
rest  principally  upon  the  psoas  and  the  quadratus  lumbo- 
rum  muscles,  and  their  position  is  oblique;  the  concave 
edge  presenting  inwards  and  forwards,  the  convex  edge 
backwards,  and  the  upper  extremity  approaching  nearer 
to  the  spine  than  the  lower. 

The  Right  Kidney  is  situated  rather  lower  than  the  left: 
it  is  below  the  posterior  part  of  the  right  lobe  of  the  liver, 
and  behind  the  duodenum  and  the  colon.  The  Left  Kidney 
is  below  the  spleen,  and  behind  the  descending  portion  of 
the  colon.  Each  of  the  kidneys  is  below  and  very  near  to 
one  of  the  glandulse  renales. 

They  are  surrounded  with  a large  quantity  of  lax  adi- 
pose membrane,  which  in  corpulent  persons  forms  a very 
large  mass  of  adeps  around  them;  while  in  the  emaciated 
they  are  surrounded  with  a membrane  almost  free  from 
fat.  Each  kidney  has  two  broad  sides,  two  extremities,  and 
two  edges.  The  side  or  surface  which  is  posterior,  when 
the  kidney  is  in  its  natural  situation,  is  rather  broader  than 
the  other.  The  upper  extremity,  or  portion,  is  also  broad 


159 


The  Kidneys. 

er  and  larger  than  the  lower.  The  edge  which  is  posterior 
and  external  is  regularly  convex;  the  anterior  edge  is  con- 
cave; but  the  concave  edge,  or  margin,  is  not  very  regu- 
lar. In  the  middle  it  is  largely  indented;  in  this  indenta- 
tion is  a deep  fissure,  which  separates  the  two  broad  sur- 
faces or  sides  of  the  gland  from  each  other;  and  here  the 
breadth  of  the  posterior  surface  is  evidently  greater  than 
the  anterior. 

Each  of  the  kidneys  receives  a large  artery,  which  pro- 
ceeds immediately  from  the  aorta,  nearly  in  a rectangular 
direction.  A vein,  which  opens  into  the  vena  cava,  accom- 
panies the  artery.  It  is  obvious,  from  the  situation  of  the 
kidneys  with  respect  to  the  great  vessels,  that  the  artery 
on  the  right  side  must  be  longer  than  that  on  the  left,  and 
that  the  reverse  of  this  must  be  the  case  with  the  veins: 
the  veins  are  also  anterior  to  the  arteries.  At  the  great 
fissure  these  vessels  divide  into  several  branches,  which 
enter  the  kidney  at  that  place.  The  branches  of  the  vein 
are  before  and  above;  those  of  the  artery  are  below,  and  in 
the  middle.  Surrounded  more  or  less  by  the  branches  of 
those  vessels,  is  a membranous  sac,  the  breadth  of  which 
extends  from  above  downwards.  This  sac  terminates  in  a 
tube  that  proceeds  from  the  lower  part  of  the  fissure  down 
to  the  bladder.  The  sac  is  denominated  the  pelvis  of  the 
kidney,  and  the  tube  a ureter:  each  of  these  parts  will 
soon  be  more  particularly  described. 

The  substance  of  the  kidney,  as  has  been  already  said, 
is  uniform  in  its  texture,  and  of  a reddish  brown  color. 
When  it  is  divided  by  an  incision  made  lengthways,  and 
from  its  convex  to  its  concave  edge,  there  appears  to  be  a 
small  difference  in  the  different  parts  of  it.  The  exterior 
part,  which  is  called  cortical,  is  rather  more  pale  in  color 
and  softer  in  consistence  than  the  internal  part.  It  varies 


160  The  Kidneys. 

in  thickness,  so  that  some  writers  have  described  it  as 
equal  to  two  lines,  and  others  to  one  third  of  the  kidney. 
In  a majority  of  subjects  it  will  be  found  between  the  two 
statements. 

The  interior  part  is  called  medullary,  or  tubular,  and 
appears  to  be  composed  of  very  fine  tubes.  These  tubes 
are  so  arranged,  that  a number  of  papillae  or  cones  are 
formed  by  their  convergence,  and  project  into  the  fissure 
of  the  kidney.  These  papillae  have  been  supposed  to  con- 
sist of  a substance  different  from  either  of  the  two  above 
mentioned,  but  they  appear  to  be  formed  merely  by  the 
tubular  part. 

The  arteries,  accompanied  by  corresponding  veins,  and 
by  nerves  and  absorbent  vessels,  after  ramifying  in  the 
fissure  of  the  kidney,  proceed  into  its  substance,  and  con- 
tinue their  arborescent  ramifications  until  they  have  arriv- 
ed very  near  the  exterior  surface.  They  are  so  uniformly 
distributed  to  the  different  parts  of  the  organ,  that  when 
the  bloodvessels  are  injected  with  wax,  and  the  substance 
of  the  kidney  is  removed  from  the  injected  matter,  as  is  the 
case  in  corroded  preparations,  the  injection  exhibits  accu- 
rately the  form  of  the  kidney. 

The  large  branches  of  the  bloodvessels  occupy  the  va- 
cuities between  the  papillae  in  the  fissure  of  the  kidney'-. 
When  they  penetrate  the  substance  of  the  kidney,  they  are 
inclosed  by  sheaths  which  are  derived  from  the  coat  of  the 
gland,  and  are  surrounded  by  membrane,  which  frequently 
contains  adeps. 

There  are  commonly  ten  or  twelve  papillae  in  the  fissure 
of  each  kidney,  but  there  are  sometimes  more  and  some- 
times less  than  this  number.  These  papillae  are  surrounded 
by  a membranous  sac  of  a corresponding  form;  the  papil- 
la being  a cone,  and  the  sac  resembling  the  upper  part  of 


Cortical  and  Tubular  Portions  of  the  Kidney.  161 

a funnel.  The  sac  is  therefore  called  an  infundibulum,  or 
calyx.  Sometimes  there  are  two  papillae  in  each  infundi- 
bulum, and  then  the  form  of  the  sac  is  not  so  regular.  The 
infundibulum  adheres  to  the  base  of  the  papilla,  but  lies 
loose  about  the  other  parts  of  it.  Each  infundibulum  com- 
municates, at  its  apex,  with  he  pelvis  of  the  kidney. 

The  Pelvis , as  has  been  already  mentioned,  is  a mem- 
branous sac  which  terminates  in  the  ureter,  exterior  to  the 
kidney.  This  sac  generally  divides  itself,  in  the  fissure  of 
the  kidney,  into  three  large  irregular  branches,  each  of 
which  very  soon  terminates  in  three  or  four  of  the  infun- 
dibula above  described.  That  portion  of  the  sac  which 
terminates  in  the  ureter,  is  exterior  to  the  kidney. 

When  the  interior  parts  of  the  kidney  are  exposed  to 
view, by  the  section  above  mentioned, after  the  arteries  and 
veins  have  been  minutely  injected,  the  cortical  part  will  be 
found  to  consist  almost  entirely  of  the  minute  ramifica- 
tions of  these  vessels.  Among  them  are  some  small  bodies, 
which  are  dispersed  through  the  substance,  like  berries  on 
a bush:  these  are  asserted  also  to  be  composed  of  vessels. 

The  tubular  part  certainly  proceeds  from  this  vascular 
cortical  substance:  for  Ruysch,and  after  him  several  other 
injectors,  have  filled  these  tubes  with  injection  thrown  into 
the  arteries. 

The  tubuli  of  which  this  part  is  composed,  seem  to 
arise  obscurely  from  the  cortical  part.  They  soon  assume 
somewhat  of  a radiated  direction,  and  are  finally  arranged 
so  as  to  form  the  papillae  or  cones  above  described. 

On  these  papillae  or  cones  some  of  them  can  be  traced, 
uniting  with  each  other,  to  form  larger  tubes,  which  termi- 
nate on  the  surfaces  of  the  papillae,  in  orifices  large  enough 
to  be  seen  distinctly.  From  these  orifices  urine  may  be 
Vol.  II.  X 


162-  Nerves  and  Lymphatics . Coat  of  the  Kidney. 

forced  out,  by  compressing  the  papillae.  On  this  account 
the  tubes  have  been  called  tubuli  uriniferi. 

In  the  foetal  state  the  kidney  is  formed  of  a number  of 
distinct  lobuli,  each  of  which  consists  of  a papilla  with  the 
cortical  matter  connected  to  its  base.  Soon  after  birth 
these  lobuli  coalesce;  and  in  two  or  three  years  the  sub- 
stance of  the  kidney  appears  uniform,  as  above  described. 
In  some  animals  this  lobulated  structure  continues  during 
life:  in  them,  and  also  in  the  foetus,  each  lobe  appears  like 
a distinct  organ.  Although  in  the  adult  kidney  this  struc- 
ture has  disappeared,  the  papillae  and  the  tubular  part  con- 
nected with  them  are  somewhat  detached  from  each  other, 
in  a manner  corresponding  to  their  original  arrangement. 

The  Nerves  of  the  Kidneys  originate  from  the  semilunar 
ganglion,  formerly  mentioned.  They  form  a plexus  round 
the  bloodvessels,  and  go  with  them  into  the  gland. 

The  kidneys  have  internal  and  external  absorbent  ves- 
sels, although  the  external  vessels  are  very  small.  These 
absorbents  pass  through  glands  in  the  lumbar  region  to 
the  thoracic  duct. 

The  proper  coat  of  the  kidney  is  said,  by  some  anato- 
mists, to  consist  of  two  laminae;  but  this  cannot  be  shown 
in  common  cases.  It  appears  simple  in  its  structure,  and 
very  flexible.  It  is  but  slightly  connected  to  the  glandular 
substance  which  it  incloses,  and  may  be  easily  peeled  off. 
It  is  reflected  inwards  at  the  fissure  of  the  kidney,  and  can 
be  traced  inwardly  to  some  distance,  forming  sheaths  for 
the  vessels.  In  this  internal  situation  it  is  very  thin. 

The  Ureters. 

The  pelvis  of  the  kidney  terminates  exteriorly  in  the 
Ureter , which  is  a membranous  cylindrical  tube,  rather 


Course  and  Structure  of  the  Ureters . 163 

flattened,  and  between  three  and  five  lines  in  diameter, 
with  some  variations  in  this  respect. 

The  Ureters  descend  from  the  pelvis  of  the  kidney  so 
as  to  pass  obliquely  across  the  psoas  muscle  and  the 
great  iliac  vessels.  They  are  behind  the  peritoneum, 
but  in  contact  with  it.  They  approach  the  pelvis  near 
the  junction  of  the  os  ileum  with  the  sacrum,  and  thence 
descend  forwards  and  inwards,  surrounded  with  loose 
cellular  membrane,  to  the  lower  part  of  the  bladder,  into 
which  they  are  inserted  at  its  external  and  posterior  part. 
They  first  penetrate  obliquely  the  muscular  coat,  and  then 
proceed  between  the  muscular  and  internal  coats,  from 
half  an  inch  to  an  inch,  in  an  oblique  direction,  from  with- 
out inwards  and  forwards,  wffien  they  terminate  by  small 
orifices  in  the  internal  coat,  each  of  which  is  at  an  equal 
distance  (rather  more  than  an  inch)  from  the  orifice  of  the 
urethra,  thus  forming  a triangle  with  it. 

The  ureters  are  said  to  have  three  coats.  The  exterior 
appears  to  be  derived  from  the  cellular  substance:  within 
it  is  another,  which  has  been  regarded  very  differently  by 
different  anatomists;  some  considering  it  as  merely  mem- 
branous, and  others  as  muscular.  If  the  ureter  be  laid 
open,  and  the  internal  coat  peeled  off,  the  muscular  struc- 
ture of  this  coat  is  often  very  perceptible. 

The  internal  coat  is  called  villous,  or  mucous,  and  is 
continued  from  the  internal  coat  of  the  bladder.  Over  this 
coat  mucus  is  constantly  spread,  which  defends  it  from 
the  acrimony  of  the  urine.  It  is  very  difficult  to  separate 
the  two  last  mentioned  coats  from  each  other. 

The  ureters  receive  bloodvessels  and  nerves  from  those 
of  the  neighboring  parts.  Their  internal  coat  is  very  vas- 
cular, and  is  also  very  sensible  of  irritation.  The  passage 


164 


Situation  of  the  Bladder. 

of  a small  urinary  calculus  can  be  traced  from  the  pelvis 
of  the  kidney  to  'he  bladder,  by  the  exquisite  pain  and 
the  spasmodic  affections  which  it  often  excites. 


SECTION  III. 

Of  the  Urinary  Bladder. 

THE  urinary  bladder  is  a large  sac,  of  a muscular  and 
membranous  structure,  which  occupies  the  anterior  part 
of  the  cavity  of  the  pelvis,  immediately  within  the  ossa 
pubis. 

The  size  of  the  bladder  is  in  a continued  state  of  varia- 
tion, according  to  the  quantity  of  urine  secreted.  When 
moderately  distended,  it  is  of  an  irregular  oval  form,  but 
rather  more  flat  at  its  lower  extremity  than  above.  It 
varies  in  form  according  to  the  different  circumstances  of 
the  pelvis  to  which  it  has  been  subjected. 

It  is  fixed  firmly  and  immovably  to  the  pelvis,  imme- 
diately within  the  symphysis  pubis;  so  that  it  is  always  to 
be  found  there  of  a larger  or  smaller  size.  It  is  sometimes 
completely  empty,  and  occupies  no  more  space  than  the 
thickness  of  its  coats  requires.  When  moderately  distend- 
ed, it  occupies  a considerable  portion  of  the  pelvis:  when 
distention  increases,  it  presses  the  parts  posterior  to  it 
against  the  sacrum,  and  extends  itself  above  the  brim  of 
the  pelvis  into  the  general  cavity,  rising  not  only  to  the 
umbilicus,  but  in  some  cases  to  the  epigastric  region. 

In  males  the  relative  situation  of  the  bladder  and  rec- 
tum is  such,  that  the  upper  and  middle  part  of  the  rectum 
is  behind  the  bladder;  but  the  lower  part  of  the  rectum. 


Muscular  Coat  of  the  Bladder.  165 

following  the  curve  of  the  os  sacrum  and  coccygis,  is  be- 
low the  posterior  part  of  the  bladder. 

In  females  the  vagina  and  uterus  are  situated  between 
the  bladder  and  rectum;  so  that  the  connection  of  these 
last  mentioned  parts  is  very  different  in  the  two  sexes. 

The  peritoneum  is  reflected  at  th  anterior  part  of  the 
brim  of  the  pelvis  from  the  ab  Nominal  muscles,  which  it 
lines,  to  the  upper  part  of  the  bladder,  which  is  generally 
contiguous  to  the  brim  of  the  pelvis.  It  continues  over  to 
the  posterior  side  of  the  bladder,  and  passes  down  upon  it 
some  distance  towards  the  lower  part;  but  before  it  has 
arrived  at  the  bottom,  it  is  reflected  towards  the  sacrum. 
In  males  it  extends  from  the  bladder  to  the  rectum,  and 
in  females  to  the  vagina  and  uterus;  so  that  there  is  a 
considerable  portion  of  the  lower  part  of  the  bladder 
which  is  not  invested  by  the  peritoneum.  It  also  follows 
that  when  the  bladder  is  extended  into  the  abdomen,  and 
rises  above  the  brim  of  the  pelvis,  that  part  of  it  which 
presents  anteriorly,  and  is  in  contact  with  the  abdominal 
muscles,  is  without  a covering  of  peritoneum,  being  be- 
low it. 

The  bladder  is  composed  of  a coat  consisting  of  mus- 
cular fibres,  of  a stratum  of  cellular  substance  immediately 
within  this,  and  of  an  internal  lining  membrane,  which  has 
been  called  villous,  but,  as  there  are  no  villi  perceptible 
on  it,  mav  be  more  properly  denominated  mucous. 

It  should  be  observed,  that,  in  addition  to  these  coats, 
the  bladder  has  a peculiar  investment  of  the  peritoneum, 
as  has  been  already  described;  and  also  of  the  common 
cellular  membrane,  which  is  placed  between  it  and  every 
part  to  which  it  is  contiguous. 

The  Muscular  Coat  of  the  Bladder  consists  of  fibres 
which  are  not  spread  over  it  of  a uniform  thickness,  but 


166 


C.v.'  tf  the  BicSJer. 

are  thin  in  some  places,  and  in  others  are  collected  in  fas- 
ciculi. They  ran  in  every  direction:  some  appear  longitu- 
dinal. others  circular,  and  some  oblique;  and  there  are 
n^rstices  between  them  which  are  occupied  bv  cellular 
membrane.  The  longitudinal  fibres  originate  from  the 
lower  part  of  the  bladder;  and  as  this  is  the  fixed  part  of 
that  viscus,  it  is  the  place  from  which  these  fibres  must 
necessarily  act.  Tnese  fibres  are  generally  exterior.  There 
is  no  arrangement  of  muscular  fibres  to  which  the  term  of 
sphincter  can  properly  be  applied:  but  many  anatomists 
have  thought  that  the  fibres  near  the  neck  of  the  bladder, 
bv  their  separate  contraction,  might  prevent  the  escape  of 
urine:  this  sentiment,  however,  is  contrary  to  that  of  se- 
veral verv  respectable  writers. 

The  direction  of  the  fibres,  taken  collectively,  is  such, 
that,  when  they  all  contract,  the  cavin'  of  the  bladder  is 
completely  obliterated. 

The  cellular  substance  between  the  muscular  and  inter- 
nal coats  is  dense.  It  yields  in  a remarkable  manner  to 
distention,  and  recovers  its  original  dimensions  verv 
easdv.  From  its  analogy  to  a similar  coat  in  the  intes- 
tines. it  is  called  the  Xerxus  Coat. 

The  fcite-nc.  Czct  of  the  bladder  is  of  a light  color  in 
the  drab  subject,  when  it  has  been  free  from  disease.  It 
has  been  called  villous  improperly;  for  the  villous  struc- 
ture is  not  apparent  upon  its  surface.  Being  continued 
from  the  integuments  of  the  body  which  are  extended 
alone  the  urethra,  it  has  been  inferred,  that  the  surface  of 
this  coat  was  formed  by  the  epidermis:  and  some  respect- 
able authors  have  sunpesed  that  they  had  seen  cases  it 
which  porr.ons  of  the  epidermis  of  the  bladder  had  sera- 
rated  and  'been  discharged:  but  these  appearances  are  verv 


Mucus  of  the  Bladder.  167 

equivocal,  and  it  is  by  no  means  certain  that  an  epidermis 
exists  there.* 

The  fasciculi  of  fibres  of  the  muscular  coat  occasion  tK?s 
coat  to  appear  very  irregular,  but  these  irregularities  cor- 
respond exactly  with  the  arrangement  of  the  fibres  of  the 
muscular  coat. 

When  the  internal  coat  is  separated  by  dissection  from 
the  muscular,  its  surface  is  very  smooth  and  uniform.  In 
the  recent  subject,  when  no  disease  has  previously  existed, 
it  is  always  spread  over  with  mucus  of  a light  color,  but 
nearly  transparent,  which  can  be  easily  scraped  off.  This 
mucus  is  spread  upon  the  surface  so  uniformly,  that  it  must 
be  derived  from  sources  which  are  situated  upon  every 
part  of  the  surface;  but  these  sources  are  not  very  obvious. 
On  the  membrane  of  the  nose  the  orifices  of  many  mucous 
ducts  are  very  visible,  but  such  orifices  are  not  to  be  seen 
on  this  surface.  Haller  mentions  that  he  has  seen  mucous 
glands  near  the  neck  of  the  bladder;  and  it  is  stated  by  the 
pupils  of  Desault,  that,  in  one  of  his  courses,  he  pointed 
out  a number  of  these  glands,  in  a subject  who  had  been 
afflicted  with  a catarrhal  affection  of  the  bladder. 

Notwithstanding  that  the  sources  of  this  mucus  are  ob- 
scure, the  quantity  of  it  is  sometimes  immense.  In  some 
cases,  where  the  secretion  is  increased  by  the  irritation  of 
a calculus  in  the  bladder,  the  urine  is  rendered  somewhat 
viscid  and  white  colored  by  the  mucus  mixed  with  it; 
which,  after  the  urine  has  been  allowed  to  remain  for 
some  tir»e,  subsides  in  such  quantities  as  demonstrates 
that  many  ounces  must  be  secreted  in  the  course  of  the 

* In  the  fauces  and  the  follicles  of  the  tonsils  an  effusion  of  coagu- 
lable  matter,  in  consequence  of  inflammation,  often  forms  crusts,  that 
may  be  mistaken  for  sloughs  of  the  integuments,  although  those  inte- 
guments remain  entire. 


168 


Orifice  of  the  Urethra. 

twenty-four  hours.  The  same  circumstances  occur,  with- 
out the  irritation  of  calculus,  in  the  disease  called  ca- 
tarrhus  vesicae.* 

It  is  probable  that,  in  healthy  persons,  a great  deal 
of  it  passes  off  unperceived,  being  dissolved  or  dif- 
fused in  tne  urine.  From  the  quantity  and  the  regular 
diffusion  of  this  mucus  on  the  surface  of  the  bladder,  there 
is  the  greatest  reason  for  believing  that  it  is  effused  from 
every  part  of  the  surface;  and  it  is  a question  that  has  not 
been  decided,  whether  it  is  discharged  from  glandular 
ducts  too  small  to  be  perceived,  or  from  the  exhalent 
extremities  of  the  bloodvessels.  It  is  probable  that  the 
use  of  it  is  to  defend  the  internal  coat  of  the  bladder  from 
the  acrimony  of  the  urine. 

The  symptoms  of  a stone  in  the  bladder,  as  well  as  of 
several  other  diseases,  evince  that  this  coat  is  endued  with 
a great  degree  of  sensibility. 

It  is  evident  that  the  essential  parts  in  the  general 
structure  of  the  bladder  are  the  muscular  coat  and  the 
internal  coat  last  described:  but  in  addition  to  the  accountof 
them,  there  are  some  other  important  circumstances  to  be 
noted  in  the  description  of  this  organ.  It  has  been  already 
stated,  that  the  form  of  the  bladder  was  an  irregular  oval, 
although  it  was  somewhat  varied  in  different  persons.  The 
oval  form  is  not  much  altered  at  the  part  called  the  neck  of 
the  bladder,  where  the  urethra  passes  off  from  it.  The  ori- 
fice of  the  urethra  is  situated  anteriorly  at  the  lowermost 
part  of  the  bladder.  On  the  lower  surface  of  th«  urethra, 
at  its  commencement,  and  on  the  bottom  of  the  bladder, 
immediately  connected  with  the  urethra,  is  situated  the 
Prostate  Gland , (to  be  hereafter  described  with  the  organs 

* In  some  cases  this  mucus  soon  becomes  putrid,  and  during'  the  pu- 
trefactive process  deposits  a substance  which  appears  to  be  calcareous 


Neck  of  the  Bladder.  169 

of  generation,)  which  is  a very  firm  body,  that  adheres 
strongly  both  to  the  bladder  and  urethra.  This  circum- 
stance gives  particular  firmness  and  solidity  to  that  part 
of  the  bladder.  It  has  also  been  observed,  that  the  bladder 
is  attached  firmly  to  the  ossa  pubis,  at  its  neck,  about  the 
origin  of  the  urethra.  Each  of  these  circumstances  have  an 
effect  upon  the  orifice  of  the  urethra;  and  when  the  blad- 
der is  opened,  and  this  orifice  is  examined  from  within,  it 
appears  to  be  kept  open  by  the  connection  of  the  bladder 
with  the  prostate,  and  has  been  very  justly  compared  to 
the  opening  of  the  neck  of  a bottle  into  the  great  cavity  of 
that  vessel.* 

The  orifices  of  the  two  ureters  are  at  equal  distances 
from  the  orifice  of  the  urethra,  and  form  with  it  the  an- 
gles of  a 'triangle.  That  part  of  the  internal  surface  of 
the  bladder  which  is  within  this  triangular  space,  is  more 
smooth  than  the  remainder  of  the  same  surface,  probably 
in  consequence  of  the  adhesion  of  the  bladder  to  the 
prostate,  and  to  other  parts  exterior  to  it. 

That  part  of  the  bottom  of  the  bladder  which  is  imme- 
diately behind  the  triangular  space,  is  rather  lower  than 
this  space;  and  but  a small  portion  of  cellular  membrane 
exists  between  it  and  the  rectum  in  males,  and  the  vagina 
in  females. 

The  upper  part  of  the  bladder  is  connected  with  the 
umbilicus  by  means  of  a ligament,  which  passes  between 

* The  late  Mr.  Lieutaud,  and  after  him  the  French  anatomists  ofthe 
present  day,  have  described  a small  tubercle  at  the  lower  and  poste- 
rior part  of  the  orifice  of  the  urethra,  which  resembles  the  uvula  in 
form.  It  has  not  been  noticed  here;  and  M.  Boyer  states,  that  it  is  often 
scarcely  perceptible.  He,  however,  makes  a remark  which  is  very  wor- 
thy of  attention,  viz.  that  it  is  very  subject  to  enlargement  in  old  peo- 
ple, forming  a tumor  which  impedes  the  discharge  of  urine.  Sabatier 
has  also  made  the  same  observation. 

Vol.  II.  Y 


170  Ligaments  and  Vessels  of  the  Bladder. 

the  peritoneum  and  the  abdominal  muscles.  This  ligament 
consists  of  three  cords.  One  of  these,  which  is  in  the  mid- 
dle, arises  from  the  coats  of  the  bladder,  and  was,  in  the 
foetus,  the  duct  called  urachus;  the  other  two,  which  are 
connected  to  the  bladder  principally  by  cellular  membrane, 
were  originally  the  umbilical  arteries.*  The  middle  cord 
is  of  a light  color  and  fibrous  structure;  it  is  thickest  at 
the  bladder,  and  gradually  diminishes  as  it  approaches 
the  umbilicus.  In  a few  instances  it  has  been  found  to  be 
hollow.  In  its  progress  to  the  umbilicus  it  becomes  more 
or  less  blended  with  the  linea  alba,  or  the  tendons  of  the 
abdominal  muscles.  The  other  cords  are  generally  solid. 
After  passing  from  the  umbilicus  to  the  bladder,  they  con- 
tinue on  the  sides  of  that  viscus,  and  finally  terminate  at 
the  hypogastric  or  internal  iliac  artery. 

In  the  very  young  subject  these  cords  are  invested  by 
distinct  processes  of  the  peritoneum,  but  their  position  is 
exterior  to  the  peritoneum. 

As  the  bladder  is  situated  very  near  most  of  the  large 
ramifications  of  the  hypogastric  artery  in  the  pelvis,  it  re- 
ceives branches  from  several  of  them;  viz.  from  the  umbi- 
lical arteries  before  they  terminate;  from  the  pudic;  from 
the  obturators,  &c.  These  branches  ramify  in  the  cellular 
membrane  exterior  to  the  muscular  coat,  and  also  in  the 
cellular  substance  between  the  muscular  and  internal 
coats.  It  has  been  conjectured , that  their  terminations  in 
exhalents  on  the  surface  of  the  bladder  are  remarkably 
numerous. 

The  veins  correspond  with  the  arteries,  but  they  are 
very  numerous  on  the  lower  and  lateral  parts  of  the  blad- 

* See  the  accounts  of  these  parts  in  the  description  of  the  Abdomen 
of  the  Foetus. 


General  Observations.  171 

der,  and  by  uniting  with  the  veins  of  the  rectum  form  a 
remarkable  plexus. 

The  Lymphatic  Vessels  of  this  organ  do  not  appear 
more  numerous  than  those  of  other  parts.  They  pass  on 
each  side  the  bladder  in  the  course  of  its  bloodvessels, 
and  unite  with  the  larger  lymphatics,  and  the  glands 
which  lie  upon  the  great  bloodvessels  on  the  sides  of  the 
pelvis. 

The  Nerves  of  the  bladder  are  derived  both  from  the 
intercostal  nerve  and  from  the  nerves  of  the  medulla  spi- 
nalis, which  pass  off  through  the  sacrum;  and  therefore  the 
bladder  is  more  affected  than  the  viscera  of  the  abdomen, 
by  injuries  of  the  medulla  spinalis. 

Tbe  action  of  the  muscular  fibres  of  the  bladder  in  expelling  urine, 
and  the  effect  of  those  fibres  which  are  situated  near  the  orifice 
of  the  urethra  in  retaining  it,  can  be  considered  with  more  ad- 
vantage after  the  structure  of  the  urethra  and  the  muscles  con- 
nected with  that  canal  have  been  described. 

It  has  been  stated,  that  the  internal  coat  of  the  bladder  is 
very  sensible;  but  it  may  be  added,  that  in  consequence  of  dis- 
ease about  the  neck  of  the  bladder,  the  natural  sensibility  ap- 
pears most  inordinately  increased.  When  the  intensity  of  pain 
which  accompanies  these  complaints,  the  frequent  recurrence 
of  paroxysms,  and  their  duration,  are  taken  into  view,  there 
seems  reason  to  believe  that  none  of  the  painful  affections  of 
the  human  race  exceed  those  which  arise  from  certain  diseases 
of  the  bladder.  Happily  these  diseases  are  not  'very  common. 

The  function  of  the  kidneys  is  to  secrete  urine,  and  that  of  the 
bladder  to  retain  it  until  the  proper  time  for  evacuation. 

The  urine  may  be  regarded  as  an  excrementitious  fluid, 
which  contains  many  substances  in  solution  that  are  constantly 
found  in  it,  and  many  others  that  are  occasionally  in  it,  which 
are  taken  as  aliment  or  medicine,  and  pass  to  the  bladder  with 
little,  if  any,  change.  The  odor  of  the  rose  l«af,  the  color  of  rhu- 
barb, Sic.  are  occasionally  perceived  in  urine. 


172 


General  Observations , 


The  substances  constantly  found  in  urine  are  numerous.  The 
chemical  account  of  the  subject  is  so  long,  that  it  cannot  be  de- 
tailed here;  but  the  student  ought  to  make  himself  acquainted 
■with  it,  and  he  will  read  with  great  advantage,  Johnson’s  His- 
tory of  /Vnimal  Chemistry,  vol.  2d,  page  363;  and  also  Thomp- 
son’s Elements  of  Chemistry,  page  333. 


173 


CHAPTER  V. 

OP  THE  MALE  ORGANS  OF  GENERATION. 

THESE  organs  consist,  1st,  of  the  Testicles,  and  their 
appendages. 

2d.  Of  certain  parts  denominated  the  Vcesicula  Semi - 
nales  and  the  Prostate  Gland,  which  are  situated  near 
the  commencement  of  the  urethra,  and  are  subservient  to 
the  purposes  of  generation. 

3d.  Of  the  Penis. 


SECTION  I. 

Of  the  Testicles  and  their  appendages. 

THE  Testicles  are  two  bodies  of  a flattened  oval  form. 
Each  of  them  has  a protuberance  on  its  upper  and  poste- 
rior part  called  Epididymis , and  is  connected  to  parts 
within  the  cavity  of  the  abdomen  by  a thick  cord,  which 
proceeds  to  it  through  the  abdominal  ring.  Each  testicle 
also  appears  to  be  contained  in  a sac,  which  is  suspended 
by  this  cord  and  covered  by  the  common  integuments. 

That  portion  of  the  common  integuments  which  forms 
the  external  covering  of  the  testicles,  is  denominated 

The  Scrotum. 

The  skin  of  the  scrotum,  although  it  is  very  often  in  a 
state  of  corrugation,  has  the  same  structure  with  that  on 
other  parts  of  the  body,  except  that  it  is  rather  thinner  and 
more  delicate.  The  superior  delicacy  of  this  portion  of  the 


*r 


174  Structure  of  the  Scrotum. 

skin  is  evinced  by  the  great  irritation  produced  bv  the 
application  of  stimulating  substances,  and  the  desquama- 
tion of  the  cuticle,  which  seems  to  be  the  effect  of  irrita- 
tion. There  are  many  sebaceous  follicles  in  this  portion  of 
skin;  and  after  puberty  there  are  often  a few  long  hairs 
growing  out  of  it,  the  bulbs  of  which  are  often  ver)T  con- 
spicuous. There  is  a small  raised  line  in  the  middle  of  this 
skin,  which  commences  at  the  root  of  the  penis,  and  pro- 
ceeds backwards,  dividing  it  into  two  equal  parts:  this  line 
is  denominated  Raphe. 

The  corrugation  which  so  often  takes  place  in  the  skin 
of  the  scrotum,  appears  to  be  occasioned  by  the  contrac- 
tion of  certain  fibres,  which  are  in  the  cellular  substance 
immediately  within  it.  This  cellular  substance  appears  to  be 
attached  in  a particular  way  to  the  skin;  and  it  also  invests 
each  testicle  in  such  a manner,  that  when  they  are  with- 
drawn a cavity  is  left  in  it.  It  has  long  been  observed,  that 
no  adipose  matter  is  found  in  this  cellular  substance;  but 
it  is  often  distended  with  water  in  hydropic  diseases. 
As  the  contraction  and  corrugation  of  the  scrotum  has 
been  imputed  to  this  substance,  it  has  been  examined  with 
particular  attention  by  anatomists,  and  very  different  sen- 
timents have  been  entertained  respecting  it.  While  some 
dissectors  have  asserted  that  muscular  fibres  could  be 
seen  in  it,  which  they  have  denominated  the  Dartos  Mus- 
cle; others  have  said  that  this  substance  was  simply  cellu- 
lar, and  without  any  muscular  fibres.  This  difference  of 
sentiment  may  possibly  have  arisen  from  the  different 
conditions  of  this  part  in  different  subjects;  for  in  some 
cases  there  are  appearances  which  seem  to  justify  the  as- 
sertion that  muscular  fibres  exist  in  this  structure. 

After  the  testicles  are  removed,  so  as  to  leave  the  cel- 
lular substance  connected  with  the  skin,  if  the  scrotum  be 


175 


Action  of  the  Dartos  Muscle. 

inverted,  and  this  substance  examined  in  a strong  light, 
many  fibres  will  appear  superadded  to  the  common  cellu- 
lar structure;  and  sometimes  their  color  can  be  distin- 
guished to  be  red.  It  is  not  asserted  that  this  will  be 
uniformly  the  case;  but  certainly  it  has  often  been  observ- 
ed in  this  way. 

The  existence  of  an  organ  which  possesses  the  power 
of  contraction,  within  the  skin  of  the  scrotum  and  connect- 
ed to  it,  is  evinced  by  the  corrugation  which  takes  place 
when  the  scrotum  is  suddenly  exposed  to  cold,  after  hav- 
ing been  very  warm.  This  corrugation  occurs  in  a very 
sudden  and  rapid  manner,  in  some  cases,  in  which  the 
wounded  scrotum  is  thus  exposed  for  the  purpose  of 
dressing:  for  example,  upon  removing  an  emollient  poul- 
tice from  this  part  some  days  after  the  operation  for  the 
cure  of  hydrops  testis,  by  incision;  if  the  air  of  the  cham- 
ber be  cool,  a motion  of  the  scrotum  will  take  place,  almost 
equal  to  the  peristaltic  movements  of  the  intestines. 

The  Arteries  of  the  scrotum  are  derived  from  two 
sources.  One  or  two  small  arteries,  which  arise  from  the 
femoral  artery,  between  Poupart’s  ligament  and  the  origin 
of  the  profunda,  are  spent  upon  it.  These  are  called  the 
external  pudic  arteries.  It  also  receives  some  small 
branches  from  the  internal  pudic  artery. 

The  Nerves  of  the  scrotum  are  principally  derived  from 
the  lumbar  nerves. 

The  Spermatic  Cord. 

The  cord  which  proceeds  to  the  testicle  through  the 
abdominal  ring,  appears  at  first  view  like  a bundle  of 
muscular  fibres;  but  it  consistg  of  an  artery  and  veins, 
with  many  lymphatic  vessels  and  nerves,  and  also  the  ex- 
cretory duct  of  the  testicle,  connected  to  each  other  by 


176  Cremaster  Muscle.  Bloodvessels  of  the  Testicle . 

cellular  substance,  and  covered  by  an  expansion  of  mus- 
cular fibres  which  are  derived  from  the  lower  edge  of  the 
internal  oblique  muscle  of  the  abdomen,  and  continue 
from  it  to  the  upper  part  of  the  testicle.  These  fibres 
constitute  the  Cremaster  Muscle. 

The  artery  above  mentioned  is  called  the  Spermatic. 
It  commonly  arises  from  the  front  of  the  aorta,  very 
near  its  fellow,  at  a small  distance  below  the  emulgents: 
and  is  not  much  larger  than  a crow’s  quill.  It  proceeds 
downwards  behind  the  peritoneum  and  before  the  psoas 
muscle  and  ureter.  While  it  is  in  contact  with  the  psoas 
muscle,  it  joins  the  ramifications  of  the  vein.  It  afterwards 
meets  the  vas  deferens,  and  proceeds  through  the  abdomi- 
nal ring  to  the  back  part  of  the  testis.  Before  it  arrives  at 
the  testis  it  divides  into  several  branches,  two  of  which 
generally  go  to  the  epididymis,  and  the  others  penetrate 
the  tunica  albuginea  on  the  upper  and  back  of  the  testicle, 
and  ramify  very  minutely  on  the  fine  membranous  parti- 
tions which  exist  in  that  body. 

In  addition  to  the  spermatic  artery,  there  is  a small  twig 
from  the  umbilical  branch  of  the  hypogastric,  which  passes 
to  the  spermatic  cord  along  the  vas  deferens. 

The  branches  of  the  spermatic  vein  are  much  larger  than 
those  of  the  artery:  several  of  them  proceed  from  the  tes- 
ticle so  as  to  correspond  with  the  arterial  branches;  and  in 
addition  to  these  there  are  many  smaller,  which  also  arise 
from  the  testicle  and  epididymis.  In  their  course  up  the 
cord  they  ramify,  and  again  unite,  so  as  to  form  a consi- 
derable plexus,  which  is  called  the  Corpus  Pampiniforme , 
and  constitutes  a considerable  part  of  the  volume  of  the 
spermatic  cord. 

As  they  proceed  upwards  they  unite  into  a few  larger 
veins;  and  finally,  on  the  psoas  muscle,  they  generally 


Lymphatics  and  Nerves  in  the  Spermatic  Cord,  1 77 

form  one  trunk,  which  continues  upwards  so  as  to  unite 
with  the  vena  cava  on  the  right  side  and  the  emulgent 
vein  on  the  left. 

Sometimes,  but  not  often,  there  are  several  spermatic 
veins  on  each  side. 

The  Lymphatic  Vessels  of  the  testicle  are  very  numer- 
ous, considering  the  size  of  the  organ.  Six  or  eigh  , and 
sometimes  more,  large  trunks  have  been  injected,  running 
upon  the  cord,  and  continuing  to  the  glands  on  the  back 
part  of  the  abdomen. 

The  Nerves  of  the  testicle  are  derived  from  those  which 
supply  the  viscera  of  the  abdomen,  and  are  to  be  found  in 
the  cord  although  they  can  scarcely  be  traced  to  the  tes- 
ticle. A small  plexus,  called  the  spermatic,  is  formed  by 
fibres  from  the  renal  plexus  and  from  the  sympathetic 
nerve.  These  fibres  accompany  the  spermatic  vessels,  and 
in  all  probability  enter  the  body  of  the  testis  and  the  epi- 
didymis. The  spermatic  cord  and  cremaster  muscle  re- 
ceive filaments  from  the  second  lumbar  nerve. 

In  addition  to  these  vessels,  the  Vas  Deferens , which 
is  much  firmer  than  either  of  them,  is  always  to  be  distin- 
guished in  the  back  part  of  the  cord. 

They  are  all  covered  in  front  and  on  the  sides  by  the 
cremaster  muscle,  which  passes  with  them  from  the  lower 
margin  of  the  internal  oblique,  through  the  abdominal  ring, 
and  continues  to  the  upper  part  of  the  external  coat  of 
the  testicle,  which  is  a sac  apparently  containing  that  or- 
gan, and  upon  this  sac  it  is  spread  out  and  terminates. 

The  Tunica  Vaginalis. 

The.  External  Coat  of  the  testicle,  which  is  commonly  call- 
ed the  Tunica  Vaginalis , is  a complete  sac  which  incloses 
the  testicle  as  the  pericardium  incloses  the  heart.  It  covers 
Vol.  II.  Z 


178 


Coats  of  the  Testicle. 

the  body  of  the  testicle  and  epididymis,  and  adheres  close- 
ly to  them.  It  is  then  reflected  from  them  so  as  to  form  a 
loose  sac,  which  appears  to  contain  them.  The  cavity  of 
the  tunica  vaginalis  commonly  extends  above  the  body  of 
the  testis  up  the  cord,  and  is  oval  or  pyriform.  This  sac  is 
so  reflected  from  the  body  of  the  testicle,  that  there  is  a 
place  on  the  upper  and  back  part  of  that  body  at  which 
the  bloodvessels  enter  it,  without  penetrating  the  sac. 

It  resembles  the  peritoneum  and  other  serous  mem- 
branes in  texture,  and  is  therefore  thin  and  delicate.  It 
always  contains  a quantity  of  moisture,  sufficient  to  lubri- 
cate the  surface  which  it  forms. 

When  the  tunica  vaginalis  is  laid  open,  the  testicle  ap- 
pears as  if  it  were  contained  in  the  posterior  part  of  its 
cavity. 

The  testicles,  as  has  been  already  stated,  are  of  a flat- 
tened oval  form.  Their  position  is  somewhat  oblique,  so 
that  their  upper  extremities  look  upwards  and  forwards, 
their  lower  extremities  downwards  and  backwards,  and 
their  edges  present  forwards  and  backwards. 

The  body  of  the  testicle  is  very  firm,  in  consequence  of 
its  inclosure  in  a very  firm  coat  called  Tunica  Albuginea. 
Upon  the  upper  and  posterior  part  of  it  is  the  protube- 
rant substance,  called  Epididymis , which  is  less  firm,  being 
exterior  to  the  tunica  albuginea.  The  bloodvessels  of  the 
testicle  pass  into  it  on  the  posterior  edge,  at  some  distance 
below  the  upper  end. 

The  Tunica  Albuginea , 

In  which  the  body  of  the  testicle  is  completely  inclosed, 
is  firm  and  dense;  and  upon  this  coat  its  particular  form 
depends.  It  is  of  a whitish  color,  and  has  a smooth  exter- 
nal surface.  It  is  thick  as  well  as  strong.  The  epididymis 


Form  and  Connections  of  the  Epididymis.  179 

is  exterior  to  it.  It  is  only  perforated  by  the  bloodvessels, 
lymphatics  and  nerves,  and  by  the  vasa  efferentia,  which 
carry  out  the  secretion  of  the  testis.  One  portion  of  the 
tunica  vaginalis  adheres  very  closely  to  it,  and  the  other 
appears  to  contain  it.  The  portion  which  adheres  to  it  is 
with  difficulty  separated,  but  it  is  a distinct  membrane. 

The  Epididymis 

Differs  in  color  from  the  testicle,  being  more  or  less 
reddish.  It  commences  at  the  upper  and  anterior  extre- 
mity of  the  testicle,  and  passes  down  the  posterior  edge  to 
the  lower  end. 

At  the  commencement  the  epididymis  is  somewhat 
rounded  in  form,  and  its  upper  part,  or  head,  has  been 
called  the  globus  major:  as  it  descends  it  lessens,  and 
about  the  middle  of  the  testicle  it  is  flattish. 

It  is  firmly  attached  to  the  body  of  the  testicle,  at  the 
upper  end,  where  the  vasa  efferentia  pass  to  it;  and  it  is  also 
attached  to  it  below;  but  at  the  middle  it  appears  nearly  de- 
tached from  it.  It  has  therefore  been  compared  to  an  arch 
resting  with  its  two  extremities  on  the  back  of  the  testis;  it 
is,  however,  in  contact  with  it  at  its  middle;  but  about  the 
middle  it  only  adheres  by  one  of  its  edges  to  the  body  of 
the  testis,  and  generally  by  its  internal  edge.  It  has  a coat 
which  is  less  firm  than  the  tunica  albuginea  of  the  testicle, 
described  on  the  last  page.  The  tunica  vaginalis  of  the 
testicle  is  so  reflected  as  to  cover  a great  part  of  the  epi- 
didymis which  is  not  in  contact  with  the  testicle,  and  also 
those  surfaces  of  the  epididymis  and  testis  which  are  in 
contact  with  each  other  and  do  not  adhere. 


180  Tubuli , Septa  and  Bloodvessels  of  the  Testicle* 


The  Body  of  the  Testicle. 

When  the  tunica  albuginea  is  cut  through,  and  the 
substance  of  the  testicle  examined,  it  appears  to  con- 
sist of  a soft  pulpy  substance  of  a yellowish  brown 
color,  which  is  divided  into  separate  portions  by  very 
delicate  septa,  attached  to  the  internal  surface  of  the 
tunica  albuginea  at  the  posterior  part  of  the  testicle.  After 
maceration,  bv  using  a fine  needle  to  detach  them  from  the 
cellular  substance,  these  threads  may  be  drawn  out  to  a 
great  length.  In  some  animals  they  are  larger  than  in  the 
human  species;  in  them,  it  is  said,  thev  are  evidently  hol- 
low, and  that  very  small  bloodvessels  appear  in  their  coats. 
When  mercury  is  injected  into  the  vas  deferens,  or  excre- 
tory duct  of  the  testis,  in  a retrograde  course,  it  can  be 
perceived  in  these  ducts  in  the  human  subject. 

These  delicate  septa,  or  partitions,  are  united  to  the  in- 
ternal surface  of  the  tunica  albuginea  at  the  posterior  part 
of  the  testicle,  at  which  place  there  is  a body  called 
Corpus  Highmorianum , which  has  been  regarded  very  dif- 
ferently by  different  anatomists.  It  is  a long  whitish  sub- 
stance, which  extends  lengthwise  on  the  posterior  part 
of  the  testis;  and  was  supposed  by  Haller  to  resemble 
one  of  the  salivary  ducts.  It  is  now,  however,  generally 
agreed  to  be  of  a cellular  structure,  and  to  contain  and 
support  the  ducts  which  pass  from  the  substance  of  the 
testicle  to  the  epididymis. 

The  bloodvessels  pass  into  the  body  of  the  testicle 
upon  these  septa,  and  are  continued  from  them  to  the  fila- 
ments or  tubes  of  which  the  body  of  the  testicle  consists. 
As  in  some  animals  bloodvessels  are  distinguished  on 
these  tubes,  there  is  the  greatest  reason  to  believe  that  a di- 
rect communication  subsists  between  them,  without  the  in- 


Structure  of  the  Testicle  and  Epididymis . 181 

tervention  of  any  other  structure,  no  other  structure  hav- 
ing been  discovered:  but  at  the  same  time  it  ought  to  be 
observed,  that  these  tubes  have  not  vet  been  injected 
from  the  bloodvessels.  Some  ingenious  anatomists  have 
injected  the  artery  going  to  the  testicle  so  successfully, 
that  the  injection  has  passed  from  it  into  the  veins 
coming  out  of  the  testicle;  but  it  is  not  now  said  by  any 
of  them,  that  they  have  filled  the  tubes  in  this  manner. 

Mercury  will  pass  into  these  vessels  from  the  excre- 
tory duct  of  the  testicle;  and  by  means  of  an  injection  in 
that  way,  the  structure  of  the  testicle  can  be  unravelled. 

This  structure  is  as  follows:  The  cavity  formed  by  the 
tunica  albuginea  is  divided  into  a number  of  apartments  by 
the  very  thin  septa,  or  partitions,  above  mentioned.  From 
the  filamentary  or  tubular  matter  which  fills  each  of  these 
chambers,  proceeds  a number  of  small  tubes  or  vessels, 
which  observe  a straight  course;  they  are  therefore  called 
Vasa  Recta.  These  vasa  recta  unite  with  each  other  and 
form  a network  on  the  back  of  the  testis,  within  the  tu- 
nica albuginea,  which  is  called  Rete  Testis.  From  this 
network  other  vessels,  from  twelve  to  eighteen  in  number, 
denominated  Vasa  EJferentia , proceed  through  the  albugi- 
nea to  the  epididymis.  These  vessels  are  convoluted  in 
such  a manner  as  to  form  bundles  of  a conical  form,  which 
arc  called  Coni  Vasculosi.  The  number  of  these  corres- 
ponds with  the  number  of  the  vasa  efferentia,  and  they 
compose  about  one  third  of  the  epididymis,  viz.  all  the 
upper  part  of  it.  The  single  tubes  which  form  each  of 
these  cones,  successively  unite  into  one  duct,  which  is 
convoluted  so  as  to  form  all  the  remainder  of  the  epidi- 
dymis. The  lower  part  of  the  epididymis  is  turned  up- 
wards on  the  back  of  the  testicle,  the  tube  gradually  en- 
larges and  is  less  convoluted,  and  finally  becomes  straight: 


182 


Diameter  of  the  Fas  Deferens. 

it  then  takes  the  name  of  Fas  Deferens , and  continues  on 
the  back  of  the  testicle  to  the  spermatic  cord.* 

A small  solitary  vessel  or  duct,  has  been  observed  by 
Haller,  Monro,  and  several  other  anatomists,  to  proceed 
from  the  upper  part  of  the  epididymis:  sometimes  it 
unites  to  the  epididymis  below,  and  sometimes  it  pro- 
ceeds upwards.  The  nature  of  this  vessel  has  not  been 
ascertained  with  certainty. 

The  Fas  Deferens 

Is  a very  firm  tube  about  two  lines  in  diameter,  which 
is  not  perfectly  cylindrical  exteriorly,  although  the  cavity 
formed  by  it  is  so.  This  cavity  is  so  small  in  diameter, 
that  it  will  only  admit  a fine  bristle.  The  coats  of  the 
duct  have,  of  course,  a considerable  thickness.  The  in- 
ternal coat  forms  a soft  surface,  analogous  to  that  of  the 
mucous  membranes:  the  external  is  firm,  and  its  texture 
resembles  that  of  cartilage.  Owing  to  the  small  size  of  the 
cavity,  the  internal  coat  has  not  been  separated  from  the 
external. 

It  passes  upwards  in  the  posterior  part  of  the  spermatic 
cord,  and  continues  with  it  through  the  abdominal  ring, 

* De  Graff  appears  to  have  been  the  first  anatomist  who  made  much 
progress  in  the  successful  investigation  of  the  structure  of  the  testicle; 
and  Haller  ought  to  be  mentioned  next  to  him,  on  account  of  the  plate 
exhibiting  this  structure,  and  the  explanation  of  it,  which  he  published 
in  the  Philosophical  Transactions  of  London,  for  1749.  This  plate  has 
been  republished  by  the  second  Monro,  in  the  Literary  and  Physical 
Essays  of  Edinburgh,  and  also  in  his  Inaugural  Thesis.  Haller  has  like- 
wise republished  it  in  his  Opera  Minora.  It  represents  not  only  the  vasa 
efferentia  and  the  cones  formed  by  their  convolutions,  but  also  the 
rete  testis  and  the  vasa  recta.  Haller  could  inject  no  further  than  this; 
but  Monro  and  Hunter  soon  after  succeeded  so  as  to  fill  a considerable 
portion  of  the  body  of  the  testicle  with  mercury,  injected  by  the  vas 
deferens. 


Course  of  the  Vas  Deferens.  183 

under  and  exterior  to  the  peritoneum;  soon  after  this  it 
leaves  the  cord  and  dips  down  into  the  cavity  of  the  pel- 
vis, forming  a curve  on  the  side  of  the  bladder,  and  pro- 
ceeding backwards,  downwards  and  inwards.  In  this  course 
it  crosses  the  ureter,  and  passes  between  it  and  the  bladder. 
On  the  lower  part  of  the  bladder  the  two  vasa  deferentia 
approach  each  other  so  gradually,  that  they  appear  to 
be  nearly  parallel.  They  proceed  forward  between  the  ve- 
siculffi  seminales,  which  are  two  bodies  irregularly  con- 
voluted, that  are  placed  in  a converging  position  with 
respect  to  each  other,  and  communicate  with  the  vasa 
deferentia.  The  vasa  deferentia  finally  terminate  almost 
in  contact  with  each  other  in  the  posterior  part  of  the 
prostate  gland,  where  they  perforate  the  urethra.  At  the 
distance  of  about  two  inches  and  a half  from  their  termi- 
nation they  enlarge  in  diameter,  and  become  somewhat 
convoluted.  At  the  posterior  margin  of  the  prostate  they 
come  in  contact  with  the  anterior  extremities  of  the  vesi- 
culae  seminales,  and  unite  with  them.  After  this  union 
they  diminish  in  size,  and  become  conical;  and  passing 
a short  distance  through  the  substance  of  the  prostate, 
during  which  they  approach  each  other  more  rapidly,  they 
penetrate  the  urethra,  so  as  to  open  in  it  on  each  side  of 
a small  tubercle,  called  the  Caput  Gallinaginis , soon  to  be 
described. 

SECTION  II. 

Of  the  Vesiculce  Seminales  and  the  Prostate  Gland. 

THE  Vesiculce  Seminales  are  two  bodies  of  a whitish 
color,  and  irregular  form,  being  broad  and  flat  at  their 
posterior  extremities,  and  terminating  in  a point  at  the 
other.  Their  surfaces  are  so  convoluted,  that  they  have 


184  Structure  of  the  Vesiculce  Seminales. 

been  compared  to  those  of  the  brain.  They  are  situated 
between  the  rectum  and  bladder,  and  are  connected  to 
each  by  cellular  membrane. 

When  the  vesiculse  seminales  are  laid  open  by  an  in- 
cision, they  appear  to  consist  of  cells  of  a considerable 
size,  irregularly  arranged;  but  when  they  are  carefully 
examined  exteriorly,  and  the  cellular  membrane  about 
them  is  detached  and  divided,  they  appear  to  be  formed 
by  a tube  of  rather  more  than  two  lines  diameter,  and  se- 
veral inches  in  length,  which  terminates,  like  the  caecum, 
in  a closed  extremity.  From  this  tube  proceed  from  ten  to 
fifteen  short  branches,  which  are  closed  in  the  same  man- 
ner. All  these  tubes  are  convoluted  so  as  to  assume  the 
form  of  the  vesiculse  seminales  above  described;  and  they 
are  fixed  in  this  convoluted  state  by  cellular  membrane, 
which  firmly  connects  their  different  parts  to  each  other. 
It  is  obvious,  that  tubes  thus  convoluted,  when  cut  into, 
will  exhibit  the  appearance  of  cells,  as  in  the  present  in- 
stance. 

This  convoluted  tube,  composing  the  vesiculae  semi- 
nales, terminates  in  a very  short  duct,  which  is  nearly  of 
the  same  diameter  with  the  vas  deferens,  and  this  duct 
joins  the  vas  deferens  so  as  to  form  an  acute  angle. 

From  the  union  of  the  vesiculse  seminales  with  the  vas 
deferens  on  each  side,  a canal,  which  seems  to  be  the 
continuation  of  the  vas  deferens,  proceeds  through  part  of 
the  prostate  to  the  urethra,  which  it  perforates.  These 
canals  are  from  eight  to  twelve  lines  in  length;  they  are 
conical  in  form,  their  largest  extremity  being  equal  to 
the  vas  deferens  at  that  part. 

If  air  or  any  other  fluid  be  injected  through  the  vas  de- 
ferens into  the  urethra,  it  will  pass  at  the  same  time  into 
the  vesiculse  seminales,  and  distend  them.  It  has  been  ob- 


185 


Function  of  the  Vesiculce  Seminales. 

served,  that  a fluid  passes  in  this  manner  much  more 
readily  from  the  vasa  deferentia  into  the  vesiculas  semi- 
nales, than  it  does  from  these  last  mentioned  organs  into 
the  duct. 

These  organs  were  generally  regarded  as  reservoirs  of 
semen,  and  analogous  to  the  gall  bladder  in  their  func- 
tions, until  the  late  Mr.  J.  Hunter  published  his  opinion 
that  they  were  not  intended  to  contain  semen,  but  to  se- 
crete a peculiar  mucus  subservient  to  the  purposes  of  ge- 
neration. 

He  states  the  following  facts  in  support  of  his  opinion. 

A fluid,  very  different  from  semen,  is  found  after  death 
in  the  vesiculse  seminales. 

In  persons  who  have  lost  one  testicle,  a considerable 
time  before  death,  the  vesiculae  seminales  on  each  side 
are  equally  distended  with  this  peculiar  fluid. 

The  sensation  arising  from  redundance  of  the  secretion 
of  the  testes,  is  referred  to  the  testes,  and  not  to  the  vesi- 
culae  seminales. 

In  some  animals,  there  is  no  connection  between  the 
vasa  deferentia  and  the  vesiculse  seminales. 

See  Observations  on  certain  parts  of  the  Animal  Eco- 
nomy, by  John  Hunter. 

The  Prostate  Gland 

Is  situated  on  the  under  and  posterior  part  of  the  neck 
of  the  bladder,  so  as  to  surround  the  lower  side  of  the 
urethra.  Its  form  has  some  resemblance  to  that  of  the 
chesnut,  but  it  has  a notch  on  the  basis  like  that  of  the 
figure  of  the  heart  on  playing  cards,  and  it  is  much  larger 
than  the  chesnut  of  this  part  of  America.  The  basis  of  this 
body  is  posterior,  and  its  apex  anterior;  its  position  is 
oblique,  between  the  rectum  and  the  symphisis  pubis.  On 
Vot.  II.  2 A 


186 


Prostate  Gland.  Penis. 


the  upper  surface  is  the  groove  occupied  by  the  urethra; 
below  there  is  in  some  cases  a small  furrow,  which,  in 
addition  to  the  notch  above,  gives  to  the  gland  an  appear- 
ance of  being  divided  into  two  lobes. 

It  adheres  to  the  urethra  and  neck  of  the  bladder.  Its 
consistence  is  very  firm  and  dense,  resembling  the  indu- 
ration of  schirrus  rather  more  than  the  ordinary  texture 
of  glands. 

This  gland  receives  small  branches  from  the  neighbor- 
ing bloodvessels,  and  has  no  artery  of  considerable  size 
exclusively  appropriated  to  it. 

As  it  lies  in  close  contact  with  the  urethra,  the  ducts 
which  pass  between  it  and  the  urethra  are  not  to  be  seen 
separate  from  these  bodies;  but  ducts  can  be  seen  in  the 
substance  of  the  gland,  which  perforate  the  urethra,  and 
open  on  the  sides  of  the  caput  gallinaginis  to  the  number 
of  five  or  six  on  each  side.  By  pressure  a small  quantity  of 
a whitish  fluid  can  be  forced  from  these  orifices,  which  is 
rather  viscid,  and  coagulable  in  alcohol. 

The  particular  use  of  this  fluid  is  not  known. 

SECTION  III. 

Of  the  Penis. 

THE  penis,  when  detached  from  the  bladder,  and  the 
bones,  to  which  it  is  connected,  and  divested  of  the  skin 
which  covers  it,  is  an  oblong  body,  which  is  rounded  at 
one  extremity  and  bifurcated  at  the  other. 

It  is  composed  of  three  parts,  viz.  two  oblong  bodies 
called  Corpora  Cavernosa , which,  at  their  commencement, 
form  the  bifurcated  portions,  and  then  unite  to  compose 
the  body  of  the  organ;  and  a third  part,  of  a spongy  tex- 
ture, which  is  connected  to  these  bodies  where  they  unite 
to  each  other,  on  the  under  side,  and  continues  attached  to 


187 


Corpora  Cavernosa  Penis. 

them  during  the  whole  extent  of  their  union,  terminating 
in  an  expanded  head  which  covers  the  anterior  extremi- 
ties of  the  corpora  cavernosa.  The  urethra  passes  from 
the  neck  of  the  bladder,  on  the  under  side  of  the  penis,  to 
its  anterior  extremity,  invested  by  this  third  body,  which 
is  therefore  called  Corpus  Spongiosum  Urethrae. 

The  two  bifurcated  extremities  are  attached  each  of 
them  to  one  of  the  crura  of  the  pubis  and  ischium;  and 
they  unite  to  form  the  body  of  the  penis  immediately  an- 
terior to  the  symphisis  pubis,  to  which  the  lower  part  of  it 
is  also  attached;  so  that  the  penis  is  firmly  connected  to  the 
middle  of  the  anterior  part  of  the  pelvis.  The  urethra 
proceeds  from  the  neck  of  the  bladder,  between  the  crura 
of  the  ischium  and  pubis  and  the  crura  of  the  penis,  to 
join  the  body  of  the  penis  at  its  commencement,  and  near 
this  place  its  connection  with  the  corpus  spongiosum  be- 
gins; so  that  there  is  a small  portion  of  the  urethra  between 
the  neck  of  the  bladder  and  the  commencement  of  the 
corpus  spongiosum,  which  is  not  covered  by  the  corpus 
spongiosum.  This  is  called  the  membranous  part  of  the 
urethra. 

The  penis,  therefore,  consists  of  two  oblong  bodies  of 
a cellular  structure,  which  originate  separately,  but  unite 
together  to  form  it;  and  of  the  urethra,  which  joins  these 
bodies  immediately  after  their  union,  and  is  invested  by  a 
spongy  covering,  which  by  its  expansion  forms  the  ante- 
rior extremity  not  only  of  the  urethra  but  of  the  whole 
penis.  These  three  bodies,  thus  arranged  and  connected, 
are  covered  by  cellular  membrane  and  skin  in  a manner 
to  be  hereafter  described. 

The  Corpora  Cavernosa , 

Which  compose  the  body  of  the  penis,  are  two  irre- 


188  Structure  of  the  Corpora  Cavernosa. 

gular  cylinders,  that  are  formed  by  a thick  dense  elastic 
membrane,  of  a whitish  ligamentous  appearance  and 
great  firmness.  They  are  filled  with  a substance  of  a 
cellular  structure,  which  is  occasionally  distended  with 
blood.  The  crura  of  these  cylindrical  bodies,  which  are 
attached  to  the  crura  of  the  ischium  and  pubis,  are  small 
and  pointed  at  the  commencement,  and  are  united  to 
the  periosteum  of  the  bones.  In  their  progress  upwards 
they  enlarge,  and  at  the  svmphisis  of  the  pubis  they 
unite  so  as  to  form  one  oblong  body,  which  retains  the 
appearance  of  a union  of  two  cylinders  applied  to  each 
other  lengthways;  for  above  there  is  a superficial  groove 
passing  in  that  direction,  which  is  occupied  by  a large 
vein:  and  below  there  is  a much  deeper  groove,  in  which 
the  urethra  is  paced.  Between  these  grooves  is  a septum 
which  divides  one  side  of  the  penis  from  the  other.  It 
appears  to  proceed  from  the  strong  membrane  which 
forms  the  penis,  and  is  composed  of  bundles  of  fibres, 
which  pass  from  one  groove  of  the  penis  to  the  other, 
with  many  intervals  between  them,  through  which  blood 
or  injection  passes  very  freely.  Sometimes  these  bundles 
of  fibres,  with  their  intervals,  are  so  regularly  arranged, 
that  they  have  been  compared  to  the  teerh  of  a comb. 
This  septum  extends  from  the  union  of  the  two  crura  to 
their  termination. 

Each  of  these  cylinders  is  penetrated  by  the  main 
branch  of  the  pudic  artery,  which  is  about  equal  in  size 
to  a crow’s  quill.  These  arteries  enter  the  corpora  caver- 
nosa near  their  union,  and  continue  through  their  whole 
extent,  sending  off  branches  in  their  course:  the  turge- 
scence  and  erection  of  the  penis  is  unquestionably  pro- 
duced by  the  blood  which  flows  through  these  vessels  into 
the  penis. 


189 


Cells  of  the  Corpora  Cavernosa. 

The  interior  structure  of  the  penis,  when  examined  in 
the  recent  subject,  is  of  a soft  spongy  nature,  and  seems 
stained  with  blood.  If  any  fluid  be  injected  through  the 
arteries  this  substance  appears  cellular,  and  may  be  com- 
pletely distended  by  it.  When  air  is  injected,  and  the 
structure  becomes  dry,  the  penis  may  be  laid  open;  the 
cellular  structure  then  appears  as  if  formed  by  a number 
of  laminae  and  of  filaments,  which  proceed  from  one  part 
of  the  internal  surface  of  the  penis  to  another,  and  form 
irregular  cells.  It  has  been  compared  to  the  lattice-work  in 
the  interior  of  bones;  and  it  is  suggested  by  M.  Roux, 
that  the  fibres  of  which  the  structure  consists  resemble 
those  of  the  strong  elastic  coat  of  the  penis.*  If  these  cells 
are  filled  with  colored  wax,  injected  by  the  artery,  and  the 
animal  substance  is  then  destroyed  by  placing  the  prepa- 
ration in  a corroding  liquor,  the  wax  which  remains  shows 
that  the  membranes  forming  the  cells  are  very  thin. 

These  cells  communicate  freely  with  each  other;  and 
therefore,  if  a pipe  be  passed  through  the  strong  coat  of 
the  penis,  the  whole  of  them  can  be  filled  from  it  by  the 
ordinary  process  of  injection. 

The  Urethra 

Is  a membranous  canal,  which  extends  from  the  neck 
of  the  bladder  to  the  orifice  at  the  extremity  of  the 
penis;  and  for  a very  great  part  of  its  length  is  invest- 
ed by  a spongy  structure,  called  the  corpus  spongiosum 
urethrae.  It  proceeds  from  the  neck  of  the  bladder  along 
a groove  in  the  upper  part  of  the  prostate;  from  the 
prostate  it  continues  between  the  crura  of  the  penis  until 
their  junction:  it  then  occupies  the  great  groove  formed  by 


* Tlie  late  J.  Hunter  thought  they  were  muscular. 


190  Corpus  Spongiosum.  Bulb.  Gians  Fenis . 

the  corpora  cavernosa  on  the  lower  side  of  the  penis,  and 
continues  to  the  orifice  above  mentioned.  At  a small  dis- 
tance from  the  prostate  gland  the  spongy  substance  which 
invests  it  commences,  and  continues  to  its  termination. 
After  this  spongy  substance  has  arrived  at  the  termina- 
tion of  the  corpora  cavernosa,  it  expands  and  forms  a 
body  of  a particular  figure  which  covers  the  extremities 
of  the  corpora  cavernosa,  and  is  denominated  the  Gians 
Penis. 

The  Corpus  Spongiosum  begins  at  the  distance  of  eight 
or  ten  lines  from  the  anterior  part  of  the  prostate.  It  is 
much  larger  at  its  commencement  than  at  any  other  part 
except  the  glans,  and  this  enlarged  part  is  called  the  Bulb. 
It  surrounds  the  whole  of  the  urethra,  and  with  the  ex- 
ception of  the  bulb  and  the  glans  penis,  is  of  a cylindrical 
figure.  It  is  formed  by  a membrane  which  has  some  re- 
semblance to  the  coat  of  the  penis,  but  is  much  thinner, 
and  by  a peculiar  spongy  substance,  which  occupies  the 
space  between  the  internal  surface  of  this  membrane  and 
the  external  surface  of  the  canal  of  the  urethra.  The 
membrane  and  the  spongy  substance  form  a coat  to  the 
urethra,  which,  with  the  exception  of  the  enlargement  be- 
fore mentioned,  is  about  two  lines  thick.  It  is  situated  in 
the  groove  on  the  lower  side  of  the  penis,  and  its  coat 
adheres  firmly  to  the  coat  of  the  penis. 

The  Bulb , or  first  enlargement  of  the  corpus  spongio- 
sum, is  oblong,  and  rather  oval  in  form;  it  is  marked  by  a 
longitudinal  depression  in  the  middle,  which  is  very  su- 
perficial. It  consists  entirely  of  the  spongy  substance  above 
mentioned. 

The  Glans  Penis  is  also  composed  of  the  same  spongy 
substance,  but  the  coat  which  covers  it  is  more  thin  and 


Structure  of  the  Corpus  Spongiosum.  191 

delicate  than  that  of  the  other  parts  of  the  urethra.  The 
lower  surface  of  the  glans  is  fitted  to  the  extremities  of 
the  corpora  cavernosa,  but  it  is  broader  than  the  corpora 
cavernosa,  and  therefore  projects  over  them  on  the  upper 
and  lateral  parts  of  the  surface  of  the  penis.  The  edge  of 
the  prominent  part  is  regularly  rounded,  and  is  denomi- 
nated the  Corona  Glandis. 

Several  small  arteries  pass  to  this  spongy  structure.  The 
pudic  artery,  as  it  passes  on  each  side  to  the  corpora  ca- 
vernosa, sends  a branch  to  the  bulb  of  the  urethra.  The 
same  vessel  in  the  substance  of  the  penis,  also  sends 
branches  to  the  urethra:  and  the  artery  on  the  back  of  the 
penis  terminates  in  small  branches,  which  penetrate  the 
substance  of  the  glans. 

By  these  vessels  blood  is  carried  to  the  spongy  sub- 
stance of  the  urethra,  which  is  occasionally  distended  in 
the  same  manner  that  the  cavernous  bodies  of  the  penis 
are  distended  during  the  erection  of  that  organ.  But  the 
cellular  structure  of  this  organ  is  not  so  unequivocal  as 
that  of  the  penis;  for  if  it  be  injected  with  colored  wax, 
and  corroded  in  the  usual  manner,  the  injected  matter 
will  exhibit  an  appearance  which  has  the  strongest  resem- 
blance to  a convoluted  vessel,  like  the  vas  deferens  in  the 
epididymis. 


The  Canal  of  the  Urethra , 

Which  conveys  the  urine  from  the  bladder,  is  a very 
important  part  of  the  urinary  organs.  It  consists  of  a \ as- 
cular  membrane  with  a smooth  surface,  which  is  perfo- 
rated by  the  orifices  of  many  mucous  follicles,  some  of 
which  are  of  considerable  size.  It  is  extremely  sensible, 


192 


Internal  Surface  of  the  Urethra. 

and  has  so  much  power  of  contraction,  that  some  persons 
have  supposed  muscular  fibres  to  exist  in  its  structure. 

It  is  differently  circumstanced  in  different  parts  of  its 
course.  While  surrounded  with  the  prostate  it  adheres 
firmly  to  that  body,  seeming  to  be  supported  by  it;  and 
here  its  diameter  is  larger  than  it  is  farther  forward.  On 
the  lower  or  posterior  side  of  this  portion  of  the  urethra, 
is  an  oblong  eminence,  called  Verumontanum , or  Caput 
Gallinaginisy  which  commences  at  the  orifice  of  the  ure- 
thra, and  continues  throughout  the  whole  portion  that 
is  surrounded  by  the  prostate  gland,  terminating  at  the 
point  of  that  body.  The  posterior  extremity  of  this  tu- 
bercle begins  abruptly,  and  soon  becomes  thick  and 
large;  anteriorly  it  gradually  diminishes  to  a line,  which 
is  sometimes  perceptible  for  a considerable  distance  in 
the  urethra,  in  a straight  forward  direction.  In  the 
upper  edge  or  top  of  this  body  is  a grove,  which  is  pro- 
duced by  a mucous  follicle;  on  the  lateral  surfaces,  ante- 
rior to  the  middle,  are  the  orifices  of  the  common  ducts 
of  the  vesiculae  seminales  and  vasa  deferentia  (see  page  1 83, 
4),  which  are  sufficiently  large  to  receive  a thick  bristle. 
Near  these,  on  each  side,  are  five  or  six  smaller  orifices  of 
the  excretory  ducts  of  the  prostate  gland.  At  a small  dis- 
tance before  the  caput  gallinaginis  are  the  openings  of  two 
ducts,  one  on  each  side,  that  lead  to  small  glandular  bo- 
dies called  Cowper’s  glands,  which  are  situated  on  each 
side  of  the  urethra  below  the  bulb,  but  are  covered  by  the 
accelerator  urina;  muscle. 

The  diameter  of  the  urethra  lessens  after  it  leaves  the 
prostate.  That  portion  of  the  canal  which  is  between 
this  gland  and  the  bulb,  without  investment,  and  there- 
fore called  the  membranous  part,  is  the  smallest  in  dia- 


meter. 


193 


Mucous  Ducts  of  the  Urethra . 

After  it  is  invested  with  the  spongy  substance  it  has  a 
small  enlargement,  and  then  continues  nearly  of  one  size 
until  it  arrives  near  the  glans  penis,  when  it  again  enlarges 
and  alters  its  form,  being  no  longer  cylindrical  but  flatten- 
ed. Its  broad  surfaces  have  now  a lateral  aspect. 

From  the  bulb  of  the  corpus  spongiosum  to  this  last 
enlargement,  the  appearance  of  the  inner  surface  of  the 
urethra  is  uniform.  The  membrane  is  thin  and  delicate, 
and  in  a healthy  subject,  who  has  been  free  from  disease 
of  these  parts,  is  of  a whitish  color;  but  bloodvessels  are 
very  perceptible  in  it.  When  it  is  relaxed,  it  appears  to  be 
thrown  into  longitudinal  wrinkles;  but  it  admits  of  consi- 
derable extension,  being  somewhat  elastic:  when  extend- 
ed, its  surface  appears  smooth,  as  if  it  were  covered  with 
an  epithelium.  Throughout  the  whole  extent  of  this  part 
of  the  urethra,  are  the  orifices  of  a great  many  mucous 
ducts  or  sinuses,  which  pass  obliquely  backwards  from  the 
surface.  Many  of  these  are  so  small  that  they  cannot  be 
penetrated  by  a bristle,  or  probe  of  that  size;  but  some  are 
larger.  It  has  not  been  observed  that  any  glandular  body 
immediately  surrounds  them,  although  they  secrete  the 
mucus  with  which  the  urethra  is  lubricated.  On  the  lower 
side  of  the  urethra,  near  the  commencement  of  the  glans 
penis,  there  is  one  or  more  of  them,  so  large  that  their 
orifices  sometimes  admit  the  point  of  a small  bougie. 

These  organs,  when  inflamed,  secrete  the  puriform  dis- 
charge which  takes  place  in  gonorrhoea.  In  a natural 
state  they  produce  the  mucus  which  is  constantly  spread 
over  the  surface  of  the  urethra,  to  defend  it  from  the  acri- 
mony of  the  urine,  and  which  passes  away  with  that  fluid 
unperceived. 

The  surface  of  the  urethra  is  endued  with  great  sensi- 
bility, and  is  therefore  liable  to  great  irritation  from  con- 
Vol.  II.  2 B 


194  Contractile  Poxver  of  the  Urethra. 

tact  with  any  rough  body  or  any  acrid  substance.  Irri- 
tation, thus  excited,  induces  a state  of  contraction,  which 
is  particularly  remarkable,  as  no  muscular  fibres  are  to  be 
seen  in  its  structure.  When  a bougie  has  been  passed  into 
the  urethra  for  a considerable  distance,  if  it  cannot  pro- 
ceed the  whole  way,  it  sometimes  happens  that  the  instru- 
ment will  be  discharged  by  a steady  uniform  motion, 
which  seems  to  proceed  from  a progressive  contraction 
of  the  urethra,  beginning  very  low  down.  At  particular 
times,  after  the  urethra  has  been  much  irritated,  it  will  not 
receive  a bougie,  although  at  other  times  a bougie  of  equal 
size  may  be  passed  to  the  bladder  without  opposition. 
This  cannot  depend  upon  that  elasticity  which  was  no- 
ticed before. 

Upon  the  two  crura  of  the  penis,  or  the  beginning  of 
the  corpora  cavernosa,  are  fixed  the  muscles  called  Erec- 
tor es  Penis , which  are  described  Vol.  I.  page  204.  These 
muscles  cover  the  crura  of  the  penis  from  their  origin  to 
their  junction,  and  not  only  compress  them,  but  also  in- 
fluence the  motion  of  the  penis  when  it  is  distended. 

The  bulb  of  the  urethra  is  covered  by  a muscular  coat, 
called  the  Accelerator  Urince , (described  in  the  page  next 
to  the  one  above  mentioned)  which  has  the  effect  of  driving 
forwards  any  fluid  contained  in  the  cavity  of  the  urethra, 
and  also  of  giving  the  same  direction  to  the  blood  in  that 
part  of  the  corpus  spongiosum.  There  is  also  the  Trans- 
versus  Perinei  on  each  side,  that  passes  transversely  from 
the  tuberosity  of  the  ischium  to  the  bulb  of  the  urethra. 
Finally  the  lower  part  of  the  sphincter  ani  muscle,  which 
is  nearly  elliptical  in  form,  is  inserted  by  its  anterior  point 
into  the  muscular  covering  of  the  bulb  of  the  urethra. 
Upon  removing  the  integuments,  these  muscles  are  in 
view;  and  the  course  of  the  urethra  from  the  bladder  is 


195 


Integuments  of  the  Penis. 

concealed,  particularly  by  the  anterior  point  of  the 
sphincter  ani.  When  the  sphincter  ani  is  dissected  away 
from  its  anterior  connections,  and  the  cellular  and  adipose 
substance,  which  is  sometimes  very  abundant,  is  also  re- 
moved, the  lower  surface  of  the  membranous  part  of  the 
urethra  may  be  brought  into  view,  as  it  proceeds  from  the 
prostate  gland  to  the  bulb  of  the  corpus  spongiosum.* 

When  the  accelerator  urinse  is  removed  from  the  bulb 
of  the  urethra,  there  will  appear  two  bodies,  which  have 
some  resemblance  to  flattened  peas.  They  lie  one  on 
each  side  of  the  urethra,  and  communicate  with  its  ca- 
vity by  means  of  a duct,  which  is  from  one  third  to  half  an 
inch  in  length.  These  are  Cowper’s  glands. 

The  penis  is  connected  to  the  symphysis  pubis  by  a li- 
gamentous substance,  which  proceeds  from  the  back  or 
upper  surface  of  the  organ  to  the  anterior  part  of  the 
symphysis,  and  connects  these  parts  firmly  to  each  other. 

Thus  constructed,  of  the  corpora  cavernosa  and  the 
urethra  with  its  corpus  spongiosum,  and  attached  to  the 
pelvis  as  above  mentioned,  the  penis  is  invested  with 
its  integuments  in  the  following  manner. 

Integuments  of  the  Penis. 

The  glans  penis,  the  structure  of  which  has  been  al- 
ready described,  is  covered  by  a continuation  of  the  skin, 
which  appears  altered  in  its  texture  so  as  to  resemble  in 
some  respects  the  skin  of  the  lips,  and  in  like  manner  is 
covered  by  a delicate  production  of  cuticle. 

* The  natural  situation  of  the  membranous  part  of  the  urethra,  and 
of  the  prostate  gland,  as  well  as  their  relative  position  with  respect  to 
the  sphincter  ani,  rectum,  &c.  can  be  best  studied  by  a lateral  view  of 
the  contents  of  the  pelvis;  which  is  to  be  obtained  by  removing  care- 
fully one  of  the  ossa  innominata,  and  dissecting  the  parts  which  were 
inclosed  by  it. 


196 


The  Prepuce « 

Around  the  corona  of  the  glans,  especially  on  its  upper 
part,  there  are  whitish  tubercles,  which  are  of  different  sizes 
indifferent  persons,  but  always  very  small.  The  skin  adheres 
firmly  to  the  whole  extent  of  the  corona  of  the  glans,  and  is 
very  delicate  in  its  structure  as  it  continues  from  the  glans 
upon  the  body  of  the  penis;  but  it  gradually  changes,  so  as  to 
assume  the  appearance  and  structure  of  common  skin,  and 
continues  in  this  state  over  the  penis.  The  adhesion  of  the 
skin  to  the  ligamentous  coat  of  the  corpora  cavernosa  also 
becomes  more  loose,  owing  to  the  quantity  and  texture  of 
the  cellular  substance  which  connects  them.  The  skin  thus 
connected  to  the  penis,  has  commonly  more  length  than 
that  organ,  even  in  its  extended  state.  In  consequence  of 
this  greater  length,  and  of  its  adhering  firmly  around  the 
corona  glandis,  it  necessarily  forms  a circular  fold  or  plait, 
which  varies  in  size  according  to  the  length  of  the  skin. 
This  fold  is  generally  situated  at  the  commencement  of 
the  firm  attachment  of  the  skin  to  the  body  of  the  penis, 
or  around  the  glans;  but  it  may  be  formed  any  where 
upon  the  body  of  the  penis  by  artificial  management. 

This  duplicature,  or  fold  of  the  skin,  when  it  takes  place 
so  as  to  cover  the  glans,  is  called  the  Prepuce;  and  the  skin 
which  is  very  tender  and  delicate  for  some  distance  from 
the  glans,  forms  that  surface  of  the  prepuce  which  is  in 
contact  with  the  glans  when  it  covers  that  body. 

There  is  also  a small  fold  of  the  skin,  which  is  longitu- 
dinal in  its  direction,  that  commences  at  the  orifice  of  the 
urethra,  and  extends  backwards,  on  the  lower  surface  of 
the  penis.  It  is  unvarying  in  its  position,  and  is  called 
the  Frenum. 

It  is  a general  observation,  that  adeps  is  not  found  in 
the  cellular  substance  which  connects  the  skin  to  the  body 


Bloodvessels  and  Absorbents  of  the  Penis.  197 

of  the  penis;  but  this  cellular  substance  is  distended  with 
water  in  some  hydropic  cases. 

From  the  skin  immediately  below  the  glans,  and  from 
small  follicles  on  each  side  of  the  frenum,  is  secreted  ah 
unctuous  fluid,  which,  when  allowed  to  continue,  becomes 
inspissated,  and  acquires  a caseous  consistence  and  color, 
as  well  as  a peculiar  odor.  It  sometimes  also  acquires  an 
acrimony  which  produces  inflammation  of  the  surface  with 
which  it  is  in  contact,  as  well  as  the  copious  secretion  of 
a puriform  fluid. 

The  distribution  of  the  pudic  artery  in  the  penis,  has 
already  been  mentioned;  and  a further  account  of  its  ori- 
gin and  progress  to  its  destination,  will  be  found  in  the 
general  account  of  the  arteries.  Sometimes  small  branches 
of  the  external  pudic  arteries,  which  originate  from  the 
femoral,  are  extended  to  the  penis;  and  it  has  been  assert- 
ed, that  branches  of  the  middle  haemorrhoidal  artery  have 
also  been  found  there,  but  this  does  not  often  occur. 

The  Veins  of  the  penis  are  of  two  kinds:  those  which 
originate  in  the  corpora  cavernosa,  accompany  the  cor- 
responding branches  of  the  pudic  artery,  but  communicate 
more  or  less  with  the  plexus  of  veins  on  the  lower  and 
lateral  parts  of  the  bladder.  There  is  also  a great  vein 
which  occupies  the  groove  on  the  back  of  the  penis,  be- 
tween the  corpora  cavernosa,  that  appears  particularly 
appropriated  to  the  corpus  spongiosum  urethrae;  for  it 
originates  in  the  glans  penis,  and  receives  branches  from 
the  urethra  as  it  proceeds  backwards.  There  are  often  two 
of  these  veins,  one  in  the  groove  and  the  other  more  su- 
perficial: they  generally  unite  near  the  root  of  the  penis. 
The  common  trunk  then  passes  between  the  body  of  the 
penis  and  the  symphysis  pubis,  and  terminates  in  a plexus 
of  veins  at  the  neck  of  the  bladder,  which  is  connected  to 


198  Nerves. — General  Observations. 

the  plexus  above  mentioned  on  the  lower  and  lateral  parts 
of  the  same  viscus. 

The  Absorbent  Vessels  of  the  penis  take  two  different 
directions  on  each  side.  Those  which  arise  from  the  inte- 
guments generally,  unite  so  as  to  form  a few  trunks  on  the 
back  of  the  penis,  which  divide  near  the  root  of  the  organ, 
and  proceed  to  the  glands  of  the  groin.  Those  which  ori- 
ginate from  the  interior  parts  of  the  penis,  accompany  the 
bloodvessels,  and  terminate  in  the  plexus  of  lymphatics  in 
the  pelvis. 

It  ought  to  be  noted,  that  the  superficial  lymphatics 
generally  enter  the  upper  inguinal  glands. 

The  Nerves  of  the  penis  are  principally  derived  from 
the  lower  sacral  nerves,  which  unite  in  the  plexus  that 
forms  the  great  ischiatic.  From  these  nerves  a branch  on 
each  side  originates,  which  passes,  like  the  pudic  artery, 
between  the  sacro-sciatic  ligaments.  In  this  course  it  di- 
vides into  two  branches,  one  of  which  passes  below  to  the 
muscles  of  the  penis  and  urethra,  and  to  the  contiguous 
parts;  and  some  of  its  branches  seem  finally  to  terminate 
in  the  dartos:  the  other  branch  proceeds  along  the  crura 
of  the  pubis  and  ischium,  and  passing  between  the  sym- 
physis pubis  and  the  body  of  the  penis,  arrives  at  the 
upper  surface  or  dorsum  of  the  penis,  along  which  it  con- 
tinues on  the  outside  of  the  arteries  to  the  glans,  in  which 
it  terminates.  In  this  course  it  sends  off  several  branches, 
some  of  which  terminate  in  the  integuments  of  the  penis. 

After  an  examination  of  the  relative  situation  of  the  mus- 
cles and  bloodvessels  of  the  male  organs  of  generation, 
there  appears  reason  to  doubt,  whether  the  erection  of 
the  penis  can  be  referred  to  pressure  upon  the  veins 
which  return  from  that  organ. — Albinus  has  written  on 
this  subject.  See  Academicarum  Annotationum,  lib.  ii 


General  Observations. 


199 


caput  xviii.  Haller  has  also  considered  it,  and  stated  the 
opinions  of  several  anatomists;  in  his  Elementa  Physi- 
ologiae,  tom.  vii.  page  555. 

The  manner  in  which  the  urine  is  confined  in  the  blad- 
der does  not  appear  to  be  clearly  understood.  The  con- 
nexion of  the  neck  of  the  bladder  with  the  prostate, 
and  the  appearance  of  the  contiguous  parts  of  the  blad- 
der, do  not  render  it  probable  that  these  parts  act  like 
a sphincter.  The  late  J.  Hunter,  who  paid  great  atten- 
tion to  the  functions  of  these  organs,  was  very  decided 
in  his  opinion  that  the  contraction  of  the  urethra  pro- 
duced the  effect  of  a sphincter  of  the  bladder.  He  has 
published  some  very  ingenious  observations  respect- 
ing the  manner  in  which  urine  is  discharged  from  the 
bladder,  in  his  Treatise  on  the  Venereal  Disease, 
part  III.  chapter  IX. 

Mr.  Hunter  also  long  since  asserted,  that  the  vascular  con- 
voluted appearance  of  the  corpus  spongiosum  urethrae 
was  more  distinct  in  the  horse  than  the  man.  In  the 
fifth  volume  of  the  Le£ons  d’Anatomie  Comparee  of 
Cuvier,  the  very  learned  and  ingenious  author  confirms 
the  declaration  of  Hunter,  respecting  the  vascular  con- 
volutions of  the  corpus  spongiosum  of  the  horse.  He 
states,  that  the  corpora  cavernosa  of  the  penis  of  the 
elephant  appear  to  be  filled  in  a great  degree  with  the 
ramifications  of  veins,  which  communicate  with  each 
other  by  such  large  and  frequent  anastomoses,  that  they 
have  a cellular  appearance.  A similar  structure  exists 
in  the  horse,  camel,  bullock,  deer,  &c.  and  in  them  all 
these  communicating  branches  can  be  distinguished 
from  those  which  extend  the  whole  length  of  the  penis. 

The  corpus  spongiosum  urethrae,  according  to  M.  Cu- 
vier, is  constructed  in  a similar  manner.  From  these 
facts  he  is  induced  to  believe  that  this  structure  per- 
vades the  whole  class  of  mammalia. 


200 


l 


CHAPTER  VI. 

OF  THE  FEMALE  ORGANS  OF  GENERATION. 

The  female  organs  of  generation  consist  of  the  Uterus 
and  Ovaries , with  their  appendages;  and  of  the  Vagina , 
with  the  structure  which  surrounds  its  external  orifice. 
The  uterus  is  situated  in  the  pelvis,  between  the  bladder 
and  rectum;  and  the  ovaries  are  on  each  side  of  it.  The 
vagina  is  a very  large  membranous  canal,  which  passes 
from  the  uterus  downwards  and  forwards,  also  between 
the  bladder  and  rectum,  and  opens  externally. 

Connected  with  the  orifice  of  the  vagina  are  several  bo- 
dies, which  are  called  the  external  parts  of  generation , in 
order  to  distinguish  them  from  the  uterus  and  ovaries, 
and  their  appendages,  and  also  from  the  canal  of  the  vagi- 
na; which  are  called  the  internal  parts. 

The  bladder  of  urine  lies  above  and  in  contact  with  the 
vagina:  the  urethra  is  also  intimately  connected  with  it. 
The  description  of  the  bladder  and  urethra  is  therefore 
placed  at  the  end  of  this  chapter. 

SECTION  I. 

Of  the  External  Parts  of  Generation. 

THE  adipose  membrane,  immediately  anterior  to  the 
symphysis  pubis,  and  on  each  side  of  it,  forms  a conside- 
rable prominence  in  females,  which,  at  the  age  of  puberty, 
is  covered  with  hair,  as  in  males.  This  prominence  is  de- 
nominated the  Mons  Veneris. 


Labia  Externa.— -Clitoris. 


201 


The  exterior  orifice  commences  immediately  below 
this.  On  each  side  of  this  orifice  is  a prominence  continued 
from  the  mons  veneris,  which  is  largest  above,  and  gradu- 
ally diminishes  as  it  descends.  These  prominences  have 
some  hair  upon  them.  They  are  called  the  Labia  Externa. 
Their  junction  below  is  denominated  the  Fourchette.  The 
space  between  the  place  of  their  junction  and  the  anus  is 
rather  more  than  an  inch  in  extent,  and  is  denominated 
the  Perineum. 

As  the  skin  which  forms  the  labia  is  continued  inter- 
nally, it  becomes  more  thin  and  soft,  and  is  covered  by  a 
more  delicate  cuticle.  It  is  also  more  or  less  florid,  and 
secretes  a peculiar  mucus. 

In  the  upper  angle,  formed  by  the  labia  externa,  is  the 
upper  extremity  and  glans  of  the  clitoris. 

The  Clitoris  is  a body  which  has  a very  strong  re- 
semblance to  the  penis,  but  there  is  no  urethra  attached 
to  it.  It  has  two  crura  of  considerable  length,  which 
originate,  like  those  of  the  penis,  from  the  crura  of 
the  pubis  and  ischium,  and  unite  at  the  symphysis  of 
the  pubis  so  as  to  form  a body,  which  is  not  much 
more  than  an  inch  in  length,  and  is  broad  in  propor- 
tion. The  extremity  of  this  organ,  called  the  Gians  of 
the  Clitoris , forms  a small  tubercle,  which  is  covered 
above  and  on  the  sides  by  a small  plait  or  told  of  the  skm, 
denominated  the  Prepuce.  These  parts  are  lubricated  by 
a secretion  similar  to  that  which  is  observed  round  the 
glans  penis. 

The  crura  of  the  clitoris  have  muscles  similar  to  the 
erectores  penis.  The  interior  structure  of  the  Clitoris  is 
very  similar  to  that  of  the  corpora  cavernosa  of  the  penis, 
or  the  corpus  spongiosum  of  the  urethra.  It  appears  con- 
structed for  a similar  distention,  and  is  indued  with  the 
Vol.  II.  2 C 


202  Nymphos. — Orifice  of  Urethra. 

Same  sensibility  as  the  penis.  The  two  lateral  parts  are 
also  separated  from  each  other  by  a septum,  resembling 
that  of  the  penis.  It  is  united  to  the  symphysis  pubis  by  a 
ligament. 

The  Prepuce  of  the  clitoris  has  a semicircular  form: 
below  its  extremities  two  folds  or  plaits  commence,  one  on 
each  side,  which  are  situated  obliquely  with  respect  to  each 
other,  so  as  to  form  an  angle.  These  folds  are  denomina- 
ted the  Nymphos. 

The  Nymphos  extend  from  the  clitoris  downwards  near- 
ly as  far  as  the  middle  of  the  orifice  of  the  vagina.  They 
are  situated  within  the  external  labia,  and  are  formed  by 
the  skin  after  it  has  become  more  delicate  in  its  texture. 
Their  surface  however  is  often  somewhat  corrugated. 
There  are  many  bloodvessels  in  their  internal  structure, 
and  it  is  supposed  they  are  occasionally  somewhat  tumid. 
They  are  flat,  and  their  exterior  edge  is  convex;  so  that 
they  are  narrow  at  their  extremities,  and  broad  in  the 
middle.  Their  breadth  is  very  variable,  and  in  some  in- 
stances is  great.  In  a majority  of  cases  it  is  equal  to  one 
fourth  of  their  length.  Their  colour  in  young  subjects  is 
of  a bright  red;  in  women  advanced  in  years  and  who 
have  had  many  children,  they  are  of  a brown  red,  and 
sometimes  of  a dark  colour. 

The  use  of  these  parts  is  not  very  evident.  They  have 
been  supposed  to  regulate  the  course  of  the  urine  as  it 
flows  from  the  urethra,  but  their  effect  in  this  respect  is 
not  great.  They  have  also  been  supposed  to  favour  the 
necessary  enlargement  of  the  parts  in  parturition. 

The  orifice  of  the  urethra  is  situated  about  an  inch  and 
one  quarter  further  inward  than  the  clitoris.  It  is  often 
rather  less  than  the  diameter  of  the  urethra,  and  is  some- 
what protuberant.  The  orifices  of  mucous  ducts  are  to  be 
perceived  around  it. 


Hymen. — Vagina.  203 

The  orifice  of  the  urethra  is  at  the  commencement  of 
the  canal  of  the  vagina.  Immediately  within  this  orifice  is 
situated  the  membrane  denominated  Hymen. 

The  Hymen  is  an  incomplete  septum,  made  by  a fold  or 
duplicature  of  the  membrane,  which  forms  the  surface  con- 
tiguous to  it.  Sometimes  it  is  circular,  with  an  aperture  in 
the  center.  Sometimes  it  has  a resemblance  to  the  crescent, 
the  aperture  being  at  the  upper  part  of  it.  The  hymen 
has  frequently  been  found  without  a perforation,  and 
has  therefore  prevented  the  discharge  of  the  menstrual 
evacuation.  It  is  generally  ruptured  in  the  first  intercourse 
of  the  sexes;  and  some  small  tubercles,  which  are  found 
on  the  surface  of  the  vagina  near  the  spot  where  it  was 
situated,  are  supposed  to  be  the  remains  of  it.  These  tu- 
bercles are  called  Carunculce  Myrtiformes. 


SECTION  II. 

Of  the  Vagina. 

THE  canal  of  the  vagina,  commencing  at  the  hymen  and 
the  orifice  of  the  urethra,  is  rather  more  narrow  at  its  be- 
ginning than  it  is  further  inward.  From  this  place  it  ex- 
tends backwards  and  upwards,  and  partakes  in  a small 
degree  of  the  curve  of  the  rectum:  while  the  bladder, 
which  is  above  it,  and  rests  upon  it,  increases  the  curva- 
ture of  the  anterior  part.  It  is  much  larger  in  women  who 
have  had  children  than  in  those  who  have  not. 

The  membrane  which  lines  the  vagina  resembles,  to  a 
certain  degree,  the  membranes  which  secrete  mucus  in 
different  parts  of  the  body.  Its  surface  appears  to  consist 
of  very  small  papillae;  and  at  the  anterior  extremity  of  the 
vagina  it  forms  a great  number  of  rugae,  which  are  arran- 


204  Corpora  Cavernosa.— Sphincter  Vagince. 

ged  in  a transverse  direction,  both  on  the  part  of  the  vagina 
connected  to  the  bladder,  and  on  that  which  is  connected 
to  the  rectum,  while  the  lateral  parts  of  the  vagina  are 
smooth.  These  rugae  are  most  prominent  in  the  middle; 
so  that  a raised  line  appears  to  pass  through  them  at  right 
angles.  This  line  extends  from  without  inwards.  The  ru- 
gae on  the  part  next  to  the  bladder  are  the  strongest. 

This  arrangement  of  the  surface  of  the  vagina  does  not 
extend  beyond  the  external  half  of  the  canal:  on  the  inter- 
nal half  part,  or  that  nearest  the  uterus,  the  surface  is 
smooth. 

The  rugae  are  considerably  diminished  in  women  who 
have  had  children. 

Throughout  this  surface  are  to  be  seen,  in  some  cases 
with  the  naked  eye,  the  orifices  of  mucous  follicles  or 
ducts,  which  occasionally  discharge  considerable  quanti- 
ties of  mucus. 

Exterior  to  this  lining  membrane  of  the  vagina  is  a 
dense  cellular  structure,  which  has  not  yet  been  completely 
investigated:  it  is  of  a lightish  colour,  and  has  some  re- 
semblance to  the  texture  of  the  body  of  the  uterus.  It  is 
very  vascular,  and  appears  to  be  of  a fibrous  structure.  It 
may  be  very  much  distended,  and  seems  to  have  a con- 
tractile power. 

At  the  anterior  extremity  of  the  vagina,  on  each  side  of 
it,  there  is,  superadded  to  this,  a cellular  or  vascular  sub- 
stance, from  eight  lines  to  an  inch  in  breadth;  which,  when 
cut  into,  resembles  the  corpora  cavernosa,  or  the  corpus 
spongiosum  of  the  penis.  These  bodies  commence  near 
the  body  of  the  clitoris,  and  extend  downwards  on  each 
side  of  the  vagina.  They  have  been  called  Plexus  Rete - 
formis , and  Corpora  Cavernosa  Vagina ?,  and  are  supposed 
to  be  occasionally  distended  with  blood,  like  ^e  clitoris 
and  penis. 


Unimpregnated  Uterus.  2(J5 

These  corpora  cavernosa  are  covered  by  muscular  fibres, 
which  pass  over  them  on  each  side  from  the  sphincter  ani 
to  the  body  of  the  clitoris;  to  each  of  which  organs  they 
are  attached*  These  fibres  constitute  the  sphincter  vaginae 
muscle,  and  contract  the  diameter  of  the  vagina  at  the 
place  where  they  are  situated. 

The  transversus  perinei  muscles  also  exist  in  the  fe- 
male. They  pass  from  the  tuberosities  of  the  ischia,  and 
are  inserted  into  a dense  whitish  substance  in  the  perine- 
um, to  which  the  anterior  extremity  of  the  sphincter  ani 
is  likewise  attached. 

The  vagina  is  in  contact  with  the  rectum  behind;  the 
bladder  lies  upon  it  and  anterior  to  it.  A small  portion  of 
peritoneum,  to  be  reflected  to  the  rectum,  is  continued 
from  the  uterus  upon  the  posterior  part  of  it.  The  lateral 
portions  of  it  are  invested  with  cellular  substance.  The 
anterior  extremity  of  the  uterus,  which  is  called  the 
Os  Tincae,  projects  into  it  from  above. 


SECTION  III. 

Of  the  Uterus , the  Ovaries  and  their  Appendages. 

The  Uterus 

HAS  been  compared  to  a pear  with  a long  neck.  There 
is  of  course  a considerable  difference  between  the  body 
and  neck;  the  first  being  twice  as  broad  as  the  last.  Each 
of  these  parts  is  somewhat  flattened. 

In  subjects  of  mature  age,  who  have  never  been  preg- 
nant, the  whole  of  the  uterus  is  about  two  inches  and  a 
half  in  length,  and  more  than  one  inch  and  a half  in  breadth 
at  the  broadest  part  of  the  body:  it  is  also  near  an  inch  in 
thickness. 


206 


Ligaments  of  the  Uterus. 

It  is  generally  larger  than  this  in  women  who  have 
lately  had  children. 

The  uterus  is  situated  in  the  pelvis  between  the  bladder 
and  rectum,  and  is  inclosed  in  a duplicature  or  fold  of  the 
peritoneum,  which  forms  a loose  septum  that  extends  from 
one  side  of  the  pelvis  to  the  other,  and  divides  it  into  an 
anterior  and  posterior  chamber.  The  posterior  surface  of 
this  septum  is  opposed  to  the  rectum,  and  the  anterior  to 
the  bladder.  The  two  portions  of  this  septum,  which  are 
between  the  uterus  and  the  lateral  parts  of  the  pedvis,  are 
called  the  Broad  Ligaments. 

On  the  posterior  surface,  the  Ovaries  are  situated  on 
each  side  of  the  uterus,  being  inclosed  by  a process  of  the 
ligament  or  septum.  Above  them,  in  the  upper  edge  of  the 
septum,  are  the  Fallopian  Tubes , which  are  ducts  that  com- 
mence at  the  upper  part  of  the  uterus  on  each  side,  and 
proceed  in  a lateral  direction  for  some  distance,  when  they 
form  an  angle  and  incline  downwards  to  the  ovaries. 
These  ducts  are  inclosed  between  the  two  laminae  of  the 
septum  for  the  greater  part  of  their  length. 

The  peritoneum,  which  forms  the  septum,  is  reflected 
from  it,  posteriorly,  to  the  rectum  and  the  posterior 
surface  of  the  pelvis,  and  anteriorly,  to  the  bladder.  In 
its  progress,  in  each  direction,  it  forms  small  plaits  or 
folds;  two  of  which  extend  from  the  uterus  to  the  rec- 
tum posteriorly,  and  two  more  to  the  bladder  anteriorly: 
these  are  called  the  Anterior  and  Posterior  Ligaments  of 
the  Uterus. 

Two  other  ligaments,  which  proceed  more  immediately 
from  the  uterus,  are  called  the  Round  Ligaments.  These 
arise  from  each  side  of  the  uterus,  at  a small  distance  be- 
fore and  below  the  origins  of  the  fallopian  tubes,  and  pro- 
ceed in  an  oblique  course  to  the  abdominal  rings.  These 


Structure  and  Cavity  of  the  Uterus.  207 

ligaments  are  also  invested  by  the  peritoneum.  They  pass 
through  the  rings  and  soon  terminate. 

In  the  body  of  the  uterus  is  a cavity  which  approaches 
to  the  triangular  form;  and  from  which  a canal  proceeds 
through  its  neck.  This  cavity  is  so  small  that  its  sides  are 
almost  in  contact,  and  the  canal  is  in  proportion;  so  that 
this  organ  is  very  thick  in  proportion  to  its  bulk. 

The  substance  of  which  the  uterus  consists  is  very  firm 
and  dense;  it  is  of  a whitish  colour,  with  a slight  tinge  of 
red.  There  are  many  bloodvessels,  with  nerves  and  ab- 
sorbent vessels,  in  its  texture.  The  nature  and  structure 
of  this  substance  has  not  yet  been  precisely  ascertained. 
It  appears  very  different  indeed  from  muscle;  but  the 
uterus  occasionally  contracts,  with  great  force,  during  la- 
bour. It  is  not  rendered  thin  by  its  enlargement  during 
pregnancy,  and  the  bloodvessels  in  its  texture  are  greatly 
enlarged  at  that  time. 

Exteriorly,  the  uterus  is  covered  by  the  peritoneum,  as 
has  already  been  mentioned.  Internally,  it  is  lined  with  a 
delicate  membrane  that  has  some  resemblance  to  those 
which  secrete  mucus,  and  is  generally  of  a whitish  co- 
lour, abounding  with  small  orifices  that  can  be  seen 
with  a magnifying  glass.  This  membrane  is  so  intimately 
connected  to  the  substance  of  the  uterus  that  some  anato- 
mists have  supposed  it  was  merely  the  internal  surface  of 
that  substance,  but  this  opinion  is  now  generally  aban- 
doned. It  is  supposed  that  the  colour  of  this  membrane 
is  more  florid  about  the  period  of  menstruation. 

The  cavity  of  the  uterus,  as  has  been  observed  before, 
is  triangular  in  form.  When  the  organ  is  in  its  natural  po- 
sition, the  upper  side  of  this  triangle  is  transverse  with 
respect  to  the  body,  and  the  other  sides  pass  downwards 
and  inwards.  In  each  of  the  upper  angles  are  the  orifices 


208  Cavity  of  the  Neck  of  the  Uterus. 

of  the  fallopian  tubes,  which  are  of  such  size  as  to  admit  a 
hog’s  bristle. 

The  two  lower  lines  of  the  triangle  are  slightly  curved 
outwards  at  their  upper  extremities;  so  that  the  upper 
angles  of  the  triangle  project  outwards,  and  the  orifices  of 
the  fallopian  tubes  are  nearer  to  the  external  surface  than 
they  otherwise  would  be. 

The  lower  angle  of  the  cavity  of  the  uterus  is  occupied 
by  the  orifice  of  the  canal,  which  passes  through  the  neck 
of  the  organ;  this  orifice  is  from  three  to  four  lines  in  di- 
ameter. The  canal  is  about  an  inch  in  length,  and  is  rather 
wider  in  the  middle  than  at  either  end.  On  the  anterior 
and  posterior  portions  of  its  surface  are  many  small  ridges 
which  have  an  arborescent  arrangement,  one  large  ridge 
passing  internally  from  the  commencement  of  the  canal, 
from  which  a number  of  other  ridges  go  off  in  a transverse 
direction.  These  ridges  extend  nearly  the  whole  length  of 
the  canal.  In  the  grooves,  between  the  ridges,  are  the 
orifices  of  many  mucous  ducts.  There  are  also  on  this 
surface  a number  of  transparent  bodies  of  a round  form, 
equal  in  bulk  to  a middle  sized  grain  of  sand;  the  nature 
and  use  of  which  is  unknown.  They  have  been  called 
Ovula  Nabothiy  after  a physiologist,  who  published  some 
speculations  respecting  their  use,  about  the  commencement 
of  the  last  century. 

The  canal  of  the  neck  of  the  uterus  is  very  different 
from  other  ducts,  for  it  seems  to  be  apart  of  the  cavity  to 
which  it  leads,  £*nd  when  the  cavity  of  the  uterus  becomes 
enlarged  in  the  progress  of  pregnancy,  this  canal  is  gradu- 
ally converted  into  a part  of  that  cavity. 

The  lower  extremity  of  the  neck  of  the  uterus  is  irre- 
gularly convex  and  tumid.  The  orifice  of  the  canal  in  it  is 
oval,  and  so  situated  that  it  divides  the  convex  surface  of 


Structure  of  the  Fallopian  Tubes , 209 

the  neck  into  two  portions,  which  are  called  the  Lips.  The 
anterior  or  upper  portion  is  thicker  than  the  other. 

This  extremity  of  the  uterus  protrudes  into  the  vagina, 
and  is  commonly  called  Os  Tincce.  As  the  anterior  por- 
tion or  lip  is  larger  and  more  tumid  than  the  posterior, 
the  vagina  extends  further  beyond  the  os  tineas  on  the  pos- 
terior part  than  on  the  anterior. 

The  Fallopian  Tubes 

Are  two  canals,  from  four  to  five  inches  in  length,  which 
proceed  between  the  laminae  of  the  broad  ligaments,  from 
the  upper  angles  of  the  uterus,  in  a transverse  direction,  to 
some  distance  from  the  uterus,  when  they  form  an  angle, 
and  take  a direction  downwards  towards  the  ovaries. 

They  are  formed,  for  a considerable  part  of  their  extent, 
by  a substance  which  resembles  that  of  which  the  uterus 
consists,  and  are  lined  by  a membrane  continued  from  the 
internal  membrane  of  the  uterus.  Their  extremities  ap- 
pear to  be  composed  of  membrane,  which  is  rendered  flo- 
rid by  the  bloodvessels  in  its  texture.  At  the  commence- 
ment their  diameters  are  extremely  small;  but  they  en- 
large in  their  progress.  This  enlargement  is  gradual  fov 
the  first  half,  and  afterwards  sudden;  the  enlarged  part  is 
more  membranous  than  the  small  part,  and  has  a bright 
red  color.  The  large  extremity  is  loose  in  the  cavity  of  the 
pelvis,  and  is  not  invested  by  the  laminae  of  the  broad 
ligaments.  Near  the  termination  the  diameter  is  often 
contracted;  after  which  the  membrane  which  forms  the  tube 
expands  into  an  open  mouth,  the  margin  of  which  consists 
of  fringed  processes:  this  margin  is  also  oblique,  as  re- 
spects the  axis  of  the  tube;  and  the  different  fringed  pro- 
cesses are  not  all  of  the  same  length;  but  the  longest  are 
in  the  middle,  and  the  others  regularly  diminish  on  each 
Vol.  II.  2 D 


210  Situation  and  Structure  of  the  Ovaries. 

side  of  them:  these  processes  constitute  the  Fimbriae  of 
the  fallopian  tubes. 

The  internal  surface  of  the  large  extremities  of  these 
tubes  is  extremely  vascular;  and  there  are  some  longitu- 
dinal fibres  of  a red  color  to  be  seen  on  it. 

The  Round  Ligaments , 

Which  have  already  been  mentioned,  are  cords  of  a 
fibrous  structure,  with  many  bloodvessels  in  them.  They 
arise  from  the  uterus  below  the  origin  of  the  fallopian 
tubes,  and  proceed  under  the  anterior  lamina  of  the  broad 
ligament  to  the  abdominal  rings,  through  which  they  pass; 
and  then  their  fibres  and  vessels  are  expanded  upon  the 
contiguous  cellular  substance. 

The  Ovaries 

Are  two  bodies  of  a flattened  oval  form;  one  of  which, 
is  situated  on  each  side  of  the  uterus  on  the  posterior  sur- 
face of  the  broad  ligament,  and  invested  completely  by  a 
process  of  the  posterior  lamina,  which  forms  a coat,  and 
also  a ligament  for  it.  The  size  of  this  organ  varies  in  dif- 
ferent subjects,  but  in  a majority  of  those  who  are  about 
the  age  of  maturity  it  is  between  ten  and  twelve  lines  in 
length.  It  is  connected  to  the  uterus  by  a small  ligament, 
or  bundle  of  fibres  of  the  same  structure  with  the  round 
ligaments,  which  is  not  more  than  two  lines  in  diameter, 
and  is  included  between  the  laminae  of  the  broad  ligament. 

The  process  of  the  broad  ligament  forms  an  external 
coat  to  the  ovary;  within  this  is  the  proper  coat  of  the  or- 
gan, which  is  a firm  membrane.  This  membrane  is  so 
firmly  connected  to  the  substance  of  the  ovary  which  it 
incloses,  that  it  cannot  be  easily  separated  from  it.  The 
oyary  is  of  a whitish  colour  and  soft  texture,  and  has 


Corpora  Lutea.  Arteries  of  the  Uterus.  211 

many  bloodvessels.  In  virgins  of  mature  age  it  contains 
from  ten  to  twenty  vesicles,  formed  of  a delicate  mem- 
brane, filled  with  a transparent  coagulable  fluid.  Some 
of  these  vesicles  are  situated  so  near  to  the  surface  of  the 
ovary  that  they  are  prominent  on  its  surface;  others  are 
near  the  center.  They  are  very  different  in  size;  the  largest 
being  between  two  and  three  lines  in  diameter,  and  others 
not  more  than  one  third  of  that  size. 

In  women  who  have  had  children,  or  in  whom  concep- 
tion has  taken  place,  some  of  these  vesicles  are  removed; 
and  in  their  place  a cicatrix  is  found. 

It  has  been  ascertained,  that  during  the  sexual  inter- 
course with  males,  one  of  these  vesicles,  which  was  pro- 
tuberant on  the  surface,  is  often  ruptured,  and  a cavity  is 
found.  A cicatrix  is  soon  formed,  where  the  membrane 
was  ruptured;  and  in  the  place  occupied  bv  the  vesicle 
there  is  a yellow  substance  denominated  Corpus  Luteum . 
This  corpus  luteum  generally  continues  until  the  middle 
of  pregnancy:  it  often  remains  during  that  state,  and  for 
some  time  after  delivery,  but  it  gradually  vanishes.  The 
cicatrization  continues  during  life. 

In  many  cases  these  cicatrices  correspond  with  the  num- 
ber of  conceptions  which  have  taken  place;  but  they  often 
exceed  the  number  of  conceptions,  and  they  have  been 
found  in  cases  where  conception  has  not  been  known  to 
have  taken  place. 

In  very  old  subjects,  where  conception  has  never  taken 
place,  the  vesicles  are  either  entirely  removed,  or  small 
dense  tubercles  only  remain  in  their  place. 

The  Arteries. 

Of  the  uterus  are  derived  from  two  very  different 
sources;  viz.  from  the  spermatic  and  from  the  hypogastric 
arteries. 


212 


Veins  of  the  Uterus. 

The  spermatic  arteries,  instead  of  passing  directly  down 
to  the  abdominal  ring,  proceed  between  the  laminae  of  the 
broad  ligament,  and  send  branches  to  the  ovaries,  which 
may  sometimes  be  traced  to  the  vesicles.  They  also  send 
branches  to  the  fallopian  tubes  and  to  the  uterus.  Those 
which  are  on  the  opposite  sides  of  the  uterus  anastomose 
with  each  other,  and  also  with  the  branches  of  the  hypogas- 
tric arteries.  There  are  also  branches  of  these  arteries  in  the 
round  ligaments,  which  accompany  them  to  their  termina- 
tion outside  of  the  abdominal  ring. 

The  principal  arteries  of  the  uterus  are  those  derived 
from  the  hypogastric,  which  sends  to  each  side  of  it 
a considerable  branch,  called  the  Uterine.  This  vessel 
leaves  the  hypogastric  very  near  the  origin  of  the  internal 
pudic,  and  proceeds  to  the  cervix  of  the  uterus:  it  passes 
between  the  laminae  of  the  broad  ligaments,  and  sends 
branches  to  the  edge  of  the  uterus,  which  penetrate  its 
texture.  The  branches  which  are  in  the  texture  of  the 
uterus  are  very  small  indeed,  in  young  subjects.  In  wo- 
men who  have  had  children  they  are  considerably  larger; 
but  during  pregnancy  they  gradually  enlarge  with  the 
growth  of  the  uterus,  and  become  very  considerable. 
These  arteries  observe  a serpentine  and  peculiarly  tor- 
tuous course.  Those  on  the  opposite  sides  anastomose 
with  each  other. 

The  Feins 

Of  the  uterus,  like  the  arteries,  form  spermatic  and 
uterine  trunks.  The  Spermatic  Vein  is  much  larger  than 
the  artery.  It  ramifies  as  in  males,  and  forms  a very 
large  plexus,  which  constitutes  the  corpus  pampiniforme. 
Many  of  the  veins  which  form  this  body,  originate  near 
the  ovary:  a considerable  number  also  come  from  the  fal- 
lopian tubes  and  the  uterus.  The  spermatic  vein  and  its 


Lymphatics  and  Nerves  of  the  Uterus.  213 

branches  are  greatly  enlarged  indeed  during  pregnancy; 
and  it  is  said  that  they  are  enlarged  in  the  same  way  during 
the  menstrual  discharge. 

The  most  important  veins  of  the  uterus  are  the  branches 
of  the  Uterine  Feins.  They  are  extremely  numerous,  and 
form  a plexus  on  the  side  of  the  uterus;  from  which  two 
or  more  uterine  veins  proceed  in  the  course  of  the  artery, 
and  join  the  hypogastric.  These  veins  also  are  greatly  en- 
larged during  pregnancy. 

The  Lymphatic  Vessels 

Of  the  uterus,  and  its  appendages,  are  very  numerous. 
In  the  unimpregnated  state,  they  are  small;  but,  during 
pregnancy,  they  increase  greatly.  They  proceed  from  the 
uterus  in  very  different  directions.  Some  that  accompany 
the  round  ligaments  go  to  the  lymphatic  glands  of  the 
groin.  Others  which  take  the  course  of  the  uterine  blood- 
vessels pass  to  glands  in  the  pelvis,  and  a third  set  follow 
the  spermatic  arteries  and  veins  to  the  glands  on  the  loins. 

The  Nerves. 

Of  the  ovaries  are  derived  from  the  renal  plexus;  and 
those  of  the  uterus  and  vagina  from  the  hypogastric 
plexus,  or  the  lower  portions  of  the  sympathetic,  and  the 
third  and  fourth  sacral  nerves. 


SECTION  III. 

Of  the  Bladder  and  Urethra. 

THE  situation  of  the  Bladder , as  respects  the  symphy- 
sis pubis,  is  nearly  alike  in  both  sexes;  but  that  part  of 
it  which  is  immediately  behind  the  insertion  of  the 
ureters  is  rather  lower  in  males  than  in  females.  The  bot- 


214 


Urethra. — Gravid  Uterus. 


tom  of  the  bladder  rests  upon  the  upper  part  of  the  vagina, 
a thin  stratum  of  cellular  substance  only  intervening: 
when  that  viscus  is  distended  it  forms  a tumour,  which 
compresses  the  vagina. 

The  ureters  are  inserted,  and  the  urethra  commences 
in  the  same  part  of  the  bladder,  in  both  sexes. 

The  length  of  the  Urethra  is  between  one  and  two 
inches.  When  the  body  is  in  the  erect  position,  it  is  nearly 
horizontal;  but  is  slightly  curved,  with  its  convexity  down- 
wards. It  is  immediately  above  the  vagina,  and  it  passes 
below  the  body  of  the  clitoris.  The  external  orifice  of  it  is 
rather  more  than  an  inch  within  the  glans  or  head  of  the 
clitoris.  This  orifice  is  somewhat  prominent  in  the  vagina. 

In  the  internal  or  lining  membrane  of  the  urethra  there 
are  many  orifices  of  mucous  follicles,  and  also  longitudinal 
wrinkles,  as  in  the  urethra  of  males.  The  diameter  of 
the  female  urethra  and  its  orifice  in  the  bladder  are  greater 
than  they  are  in  the  male.  For  this  reason  it  has  been 
supposed,  that  women  are  less  liable  to  calculus  of  the 
bladder  than  men.* 

The  urethra  is  intimately  connected  with  the  external 
coat  of  the  vagina,  and  between  them  there  is  a spongy 
cellular  substance  which  makes  the  rough  surface  of  the 
vagina  prominent;  so  that  the  urethra  has  been  supposed, 
although  erroneously,  to  be  invested  with  a prostate.  It 
is  capable  of  great  artificial  dilatation. 

Of  the  Changes  induced  in  the  Uterus  in  the  progress  of 
Pregnancy. 

The  alteration  which  takes  place  in  the  size  of  the  ute- 
rus during  pregnancy  is  truly  great.  About  the  conclusion 

* It  lias  however  been  asserted  that  they  are  also  less  liable  to  cal- 
culi in  the  kidneys. 


215 


Gradual  Change  in  the  Gravid  Uterus. 

of  that  period,  instead  of  the  small  body  above  described, 
which  is  almost  solid,  the  uterus  forms  an  immense  sac, 
which  extends  from  the  termination  of  the  vagina  in  the 
pelvis,  into  the  epigastric  region;  and  from  one  side  of  the 
abdomen  to  the  other;  preserving,  however,  an  ovoid  figure. 

This  change  is  so  gradual  at  first,  that  the  uterus  does 
not  extend  beyond  the  cavity  of  the  pelvis  before  the  third 
month,  although  at  the  end  of  the  seventh  month  it  is  very 
near  the  epigastric  region. 

For  the  first  six  months  the  body  of  the  uterus  appears 
principally  concerned  in  the  enlargement:  after  this  the 
cervix  begins  to  change,  and  is  gradually  altered,  so  as  to 
compose  a portion  of  the  sac,  rather  of  less  thickness  than 
the  rest  of  the  uterus;  the  mouth  being  ultimately  an  aper- 
ture in  a part  which  is  much  thinner  than  the  other  por- 
tions of  the  organ. 

The  change  which  takes  place  in  the  texture  of  some  of 
the  appendages  of  the  uterus  is  very  important. 

The  Broad  Ligaments , which  seem  particularly  calcu- 
lated to  favor  the  extension  of  the  uterus,  are  necessarily 
altered  by  the  change  in  the  size  of  that  organ,  but  not  en- 
tirely done  away.  The  portion  of  peritoneum  of  which 
they  are  formed  must  be  very  much  enlarged  with  the 
growth  of  the  uterus,  as  it  continues  to  cover  it.  The 
Round  Ligaments  are  much  elongated;  and  they  observe 
a more  straight  course  to  the  abdominal  ring.  The  Fallo- 
pian Tubes  are  enlarged;  and  instead  of  passing  off  late- 
rally from  the  uterus,  they  now  proceed  downwards  by 
the  side  of  it.  The  Ovaries  appear  rather  larger  and  more 
spongy:  their  relative  situation  is  necessarily  lower. 

The  change  in  the  Uterus  itself  is  particularly  interest- 
ing. The  great  increase  of  its  size  is  not  attended  with 
any  considerable  diminution  of  thickness  in  its  substance; 


i 


216 


General  Observations. 


nor  are  the  arteries  much  less  convoluted  than  before  preg- 
nancy, as  might  have  been  expected.  They  are  greatly 
enlarged  in  diameter,  and  the  orifices  of  the  exhalent  ves- 
sels on  the  internal  surface  of  the  uterus  are  much  more 
perceptible. 

The  veins  are  much  more  enlarged  than  the  arteries, 
-and  in  some  places  appear  more  than  half  an  inch  in  dia- 
meter. They  are  not  regularly  cylindrical,  but  rather  flat. 
They  anastomose  so  as  to  form  an  irregular  net  work. 

The  uterus  appears  much  more  fibrous  and  muscular 
in  the  gravid  than  in  the  unimpregnated  state.  The  con- 
tractile power  of  the  gravid  uterus  is  not  only  proved  by 
the  expulsion  of  its  contents,  but  also  by  very  vigorous  con- 
tractions, which  are  occasionally  observed  by  accoucheurs. 

Although  the  general  effects  which  result  from  the  par- 
ticular conditions  of  the  uterus  in  pregnancy,  menstru- 
ation, &c.  evince  that  the  influence  of  this  organ  upon 
the  whole  system  is  very  great,  yet  it  seems  probable 
that  the  sexual  peculiarities  of  females  are  especially 
dependent  upon  the  ovaria. 

This  sentiment  is  confirmed  by  an  account  of  a wo- 
man in  whom  the  ovaria  were  deficient,  which  is  pub- 
lished in  the  London  Philosophical  Transactions  for 
1805,  by  Mr.  C.  Pears.  The  subject  lived  to  the  age  of 
twenty-nine  years.  She  ceased  to  grow  after  the  age  of 
ten  years,  and  therefore  was  not  more  than  four  feet 
six  inches  in  height:  her  breadth  across  the  hips  was 
but  nine  inches,  although  the  breadth  of  the  shoulders 
was  fourteen.  Her  breasts  and  nipples  never  enlarged 
more  than  they  are  in  the  male  subject.  There  was 
no  hair  on  the  pubes,  nor  were  there  any  indications  of 
puberty  in  mind  or  body.  She  never  menstruated.  At 
the  age  of  twenty-nine  she  died  of  a complaint  in  the 
breast,  attended  with  convulsions.  The  uterus  and  os 


Peculiarity  of  the  Female  Hottentots.  217 

tincae  were  found  not  increased  beyond  their  usual  size 
during  infancy.  The  cavity  of  the  uterus  was  of  the 
common  shape,  but  its  coats  were  membranous.  The 
Fallopian  Tubes  were  pervious.  “ The  Ovciria  were  so 
indistinct  that  they  rather  showed  the  rudiments  which 
ought  to  have  formed  them , than  any  part  of  the  natural 
structure .” 

Another  case,  which  confirms  the  aforesaid  sentiment, 
is  related  in  one  of  the  French  periodical  publications. 

It  has  been  long  known  that  a race  of  savages  near  the 
Cape  of  Good  Hope  were  distinguished  from  the  gene- 
rality of  their  species  by  a peculiarity  about  the  puden- 
dum. An  account  of  this  structure  has  been  given  with 
some  precision  by  Messrs.  Peron  and  Lesueur,  in  a paper 
which  was  read  to  the  National  Institute  of  France.  It 
is  a flap  or  apron,  four  inches  in  length,  which  is  united 
to  the  external  labia  near  their  upper  angle,  and  hangs 
down  before  the  clitoris  and  the  external  orifice  of  the 
parts  of  generation.  It  is  divided  below  into  two  lobes, 
which  cover  the  orifice.  It  is  formed  by  a soft  distensi- 
ble skin,  free  from  hair,  which  is  occasionally  corru- 
gated like  the  scrotum,  and  is  rather  more  florid  than 
the  ordinary  cutis.* 

The  Abdomen  of  the  Foetus. 

The  difference  between  the  fretus  and  the  adult,  in  the 
cavity  of  the  abdomen,  is  very  conspicuous  at  the  first 
view. 

* This  paper  has  not  yet  been  published  by  the  Institute,  but  it  is 
referred  to  by  M.  Cuvier  in  his  Legons  d’Anatomie  Comparee,  vol.  v. 
page  124. — Messrs  Peron  and  Lesueur  were  naturalists  who  accom- 
panied captain  Baudin  in  his  voyage  of  discovery. 

Vol.  II.  2 E 


218  Peculiarities  in  the  Abdomen  of  the  Foetus. 

The  Liver  in  the  foetus  is  so  large  that  it  occupies  a very 
considerable  part  of  the  abdomen.  Its  left  lobe,  which  is 
larger  in  proportion  than  the  right,  extends  far  into  the 
left  hypochondriac  region. 

The  Bladder  of  urine , when  filled,  extends  from  the 
cavity  of  the  pelvis  a considerable  distance  towards  the 
umbilicus;  so  that  the  greatest  part  of  it  is  in  the  cavity 
of  the  abdomen.  A ligament  of  a conical  figure  extends 
from  the  center  of  the  upper  part  of  the  bladder  to  the 
umbilicus;  with  an  artery  on  each  side  of  it,  which  is  soon 
to  be  described.  This  ligament,  which  is  in  the  situation 
of  the  urachus  of  the  foetus  of  quadrupeds,  is  hollow,  and 
thus  frequently  forms  a canal,  which  has  a very  small 
diameter,  that  communicates  with  the  bladder  by  an  aper- 
ture still  smaller,  and  continues  a short  distance  from  the 
bladder  towards  the  umbilicus.  In  a few  rare  instances 
this  canal  has  extended  to  the  umbilicus,  so  that  urine  has 
been  discharged  through  it,  but  the  ligament  is  commonly 
solid  there. 

The  Stomach  appears  to  be  more  curved  in  the  foetus 
than  in  the  adult. 

The  Great  Intestine  does  not  extend  sufficiently  far,  be- 
yond the  insertion  of  the  ileon,  to  form  the  caecum  com- 
pletely. 

The  Glandules  Renales  are  much  larger  in  proportion  in 
the  foetus  than  in  the  adult.  The  color  of  the  fluid  they 
contain  is  more  florid. 

The  Kidneys  are  lobulated. 

The  Testicles  in  the  foetus  are  found  above  the  pelvis, 
in  the  lumbar  region,  behind  the  peritoneum,  until  two 
months  before  birth.  Thus  situated,  their  bloodvessels  and 
nerves  proceed  from  sources  which  are  near  them;  but  the 


219 


Descent  of  the  Testicle  in  the  Foetus. 

vas  deferens,  being  connected  to  the  vesiculae  seminales  by 
one  extremity,  is  necessarily  in  a very  different  situation 
from  what  it  is  in  the  adult:  it  proceeds  from  the  testicle 
downwards  to  the  neck  of  the  bladder. — While  each 
testicle  is  in  this  situation,  it  is  connected  with  a sub- 
stance or  ligament,  called  Gubernaculum,  of  a conical  or 
pyramidical  form,  attached  to  its  lower  end,  and  extends 
from  it  to  the  abdominal  ring.  This  substance  is  vas- 
cular, and  of  a fibrous  texture:  its  large  extremity  ad- 
heres to  the  testicle,  its  lower  and  small  extremity 
passes  through  the  abdominal  ring,  and  appears  to  ter- 
minate in  the  cellular  substance  exterior  to  that  open- 
ing, like  the  round  ligament  in  females.  The  Guber- 
naculum, as  well  as  the  testicle,  is  behind  the  peritoneum; 
and  the  peritoneum  adheres  to  each  of  them  more  firmly 
than  it  does  to  any  of  the  surrounding  parts.  It  seems 
that,  by  the  contraction  of  the  Gubernaculum , the  testicle 
is  moved  down  from  its  original  situation  to  the  abdo- 
minal ring,  and  through  the  abdominal  ring  into  the 
scrotum.  The  peritoneum,  which  adheres  firmly  to  the 
gubernaculum  and  testicle,  and  is  loosely  connected  to  the 
other  parts,  yields  to  this  operation;  and  when  the  testicle 
has  arrived  near  the  abdominal  ring,  a portion  of  the  pe- 
ritoneum is  protruded  a little  way  before  it  into  the  scro- 
tum; forming  a cavity  like  the  finger  of  a glove.  The  tes- 
ticle passes  down  behind  this  process  of  the  peritoneum, 
and  is  covered  by  it  as  it  was  in  the  abdomen.  Although  it 
appears  protruded  into  the  cavity,  it  is  exterior  to  it,  and 
behind  it;  and  the  vessels,  See.  which  belong  to  the  testi- 
cle are  also  exterior  to  it. 

The  cavity  formed  in  the  scrotum,  by  this  process  of  the 
peritoneum,  necessarily  communicates  with  the  cavity  of 


220 


Umbilical  Vessels , 


the  abdomen  at  its  formation;  but  very  soon  after  the 
testicle  has  descended  into  the  scrotum,  the  upper  part  of 
this  cavity  is  closed  up,  while  the  lower  part  of  the  process 
continues  unchanged,  and  constitutes  the  Tunica  Vaginalis 
Testis.  In  some  instances  the  upper  part  of  this  process 
does  not  close  up,  and  the  communication  with  the  cavity 
of  the  abdomen  continues.  The  descent  of  the  intestine 
into  the  cavity  thus  circumstanced,  constitutes  that  species 
of  hernia  which  is  denominated  Congenital 

The  most  important  peculiarities  in  the  abdomen  of 
the  feetus  are  those  connected  with  the  circulation  of  the 
blood. 

The  internal  iliac  or  hypogastric  arteries  are  larger  than 
the  external  iliacs.  Their  main  trunks  are  continued  on 
each  side  of  the  bladder  to  its  fundus;  and  proceed  from 
it,  with  the  ligament,  to  the  umbilicus;  when  they  pass 
out  of  the  abdomen  to  go  along  the  umbilical  cord  to  the 
placenta.  These  arteries  are  now  denominated  the  Umbili- 
cal^ and  are  very  considerable  in  size.  After  birth,  as  there 
is  no  circulation  in  them,  they  soon  begin  to  change:  the 
cavity  of  them  is  gradually  obliterated,  and  they  are  con- 

* These  interesting  circumstances  respecting  the  original  situation 
of  the  testicle,  and  its  descent  into  the  scrotum,  were  discovered  and 
elucidated  by  Haller,  Hunter,  Pott,  Camper,  and  several  other  very 
respectable  anatomists  and  surgeons.  There  is  howe\rer  a difference 
of  opinion,  between  some  of  them,  as  to  the  time  when  the  testicle 
leaves  the  abdomen.  Haller  thought  the  testicles  were  seldom  in  the 
scrotum  at  birth.  Hunter  and  Camper  found  them  so  generally. 

It  has  been  suggested  that  there  are  some  national  peculiarities  in 
this  respect;  that  amongst  the  Hungarians,  for  example,  the  testicles 
often  remain  above  the  abdominal  ring  until  near  the  age  of  puberty. 

The  student  will  find  an  interesting  description  of  the  situation  of 
the  testis,  and  its  descent,  in  the  feetus,  in  the  “ Observations  on  cer- 
tain parts  of  the  Animal  .Economy,”  by  John  Hunter. 


Ductus  Venosus.  221 

verted  into  ligaments.  They  are  exterior  to  the  peritoneum, 
and  contained  in  a duplicature  of  it. 

A vein  also  called  the  Umbilical , which  is  much  larger 
in  diameter  than  both  of  the  arteries,  returns  from  the 
placenta  along  the  cord,  and  enters  the  cavity  of  the  ab~ 
domen  at  the  umbilicus.  It  proceeds  thence,  exterior  to 
the  peritoneum,  but  in  a duplicature  of  it  called  the  Fal- 
ciform Ligament , to  the  liver,  and  enters  that  viscus  at  the 
great  fissure;  along  which  it  passes  to  the  left  branch  of 
the  sinus  of  the  vena  portarum,  into  which  it  opens  and 
discharges  the  blood  which  flows  through  it  from  the 
placenta.  It  opens  on  the  anterior  side  of  the  branch  of  the 
vena  portarum,  and  from  the  posterior  side  of  the  branch* 
opposite  to  this  opening,  proceeds  a duct  or  canal,  which 
opens  into  the  left  hepatic  vein  near  its  junction  with  the 
vena  cava.  This  communicating  vessel  is  called  the  Duc- 
tus, or  Canalis  Venosus;  to  distinguish  it  from  the  duct 
which  passes  from  the  pulmonary  artery  to  the  aorta,  and 
is  called  Ductus , or  Canalis  Arteriosus.  This  venous  duct 
carries  some  of  the  blood  of  the  umbilical  vein  directly  to 
the  vena  cava;  but  it  is  much  smaller  than  the  umbilical 
vein,  and  of  course  a considerable  quantity  of  the  blood 
which  passes  through  the  umbilical  vein  must  pass  through 
the  liver,  by  the  vena  portarum,  before  it  can  enter  the 
cava. 

In  some  foetal  subjects,  if  a probe  of  sufficient  length  be 
introduced  within  the  umbilical  vein  and  pushed  forwards, 
it  will  pass  to  the  heart  without  much  difficulty  or  oppo- 
sition, as  if  it  proceeded  along  one  continued  tube,  although 
it  really  passes  from  the  umbilical  vein  across  the  branch  of 
the  vena  portarum,  and  then  through  the  ductus  venosus, 
and  through  a portion  of  the  left  hepatic  vein,  into  the 
inferior  vena  cava. 


222  Object  of  the  Circulation  in  the  Placenta. 

If  the  umbilical  vein  be  injected  with  a composition, 
which  will  be  firm  when  cool,  it  appears  to  terminate  in  a 
rounded  end,  which  is  situated  in  the  transverse  fissure 
of  the  liver:  the  sinus  of  the  vena  portarum,  into  which 
this  vein  enters,  appears  like  two  branches  going  off, 
one  from  each  side  of  it,  and  the  ductus  venosus  like 
a branch  continuing  in  the  direction  of  the  main  trunk 
of  the  umbilical  vein. 

The  umbilical  vein,  in  its  progress  through  the  fissure 
of  the  liver,  before  it  arrives  at  the  sinus  of  the  vena  por- 
tarum, sends  off  a considerable  number  of  branches  to 
each  of  the  lobes  of  that  organ,  but  more  to  the  left  than 
to  the  right  lobe. 

After  birth,  when  blood  ceases  to  flowthrough  the  um- 
bilical vein,  it  is  gradually  converted  into  a ligament;  and 
the  venous  duct  is  also  converted  into  a ligament  in  the 
same  manner.  The  vena  portarum,  which  before  appeared 
very  small,  when  compared  with  the  umbilical  vein,  now 
brings  all  the  blood  which  fills  its  great  sinus,  and  increases 
considerably  in  size. 

It  has  been  ascertained  by  anatomical  investigation, 
that  the  umbilical  arteries  above  mentioned,  after  ramify- 
ing minutely  in  the  placenta,  communicate  with  the  minute 
branches  of  the  umbilical  vein;  and  it  is  probable  that  the 
whole  blood  carried  to  the  placenta  by  these  arteries,  re- 
turns by  the  umbilical  vein  to  the  fcetus. 

It  is  clearly  proved  by  the  effects  of  pressure  on  the 
umbilical  cord,  in  cases  of  delivery  by  the  feet,  as  well  as  by 
other  similar  circumstances,  that  this  circulation  cannot  be 
suspended  for  any  length  of  time  without  destroying  the 
life  of  the  fcetus.  From  these  circumstances,  and  from  the 
florid  color  which  the  blood  acquires  by  circulating  in  the 


Object  of  the  Circulation  in  the  Placenta.  223 

placenta,  it  seems  probable  that  the  object  of  the  circula- 
tion through  that  organ  is  somewhat  analogous  to  the 
object  of  the  pulmonary  circulation  through  the  lungs 
of  adults.* 

* During  the  first  four  months  of  pregnancy  a very  small  vesicle, 
which  does  not  exceed  the  size  of  a pea,  is  found  between  the  chorion 
and  the  amnios,  near  the  insertion  of  the  umbilical  cord  into  the  pla- 
centa. It  is  connected  to  the  foetus  by  an  artery  and  a vein,  which  pass 
from  the  abdomen  through  the  umbilicus,  and  proceeding  along  the 
cord  to  the  placenta,  continue  from  it  to  the  vesicle.  The  artery  arises 
from  the  mesenteric,  and  the  vein  is  united  to  the  mesenteric  branch 
of  the  vena  portarum.  It  is  probable  that  these  vessels  commonly  exist 
no  longer  than  the  vesicle,  viz.  about  four  months;  but  they  have  been 
seen  by  Haller  and  Chaussier  at  the  termination  of  pregnancy.  They 
are  called  Omphalo  Mesenteric  vessels.  The  vesicle  is  denominated  the 
Umbilical  Vesicle. 

This  inexplicable  structure  is  delineated  in  Hunter’s  Anatomy  of  the 
Gravid  Uterus,  plate  xxxiii.  figures  v.  and  vi.;  in  the  Academical  Anno- 
tations of  Albinus,  first  book,  plate  i.  figure  xii.;  and  also  in  the  leones 
Embryonum  Humanorum  of  Soemmering,  figure  ii. 


SYSTEM  OF  ANATOMY. 


PART  IX. 

OF  THE  BLOODVESSELS. 

The  Bloodvessels  are  flexible  tubes,  of  a peculiar 
texture,  through  which  blood  passes  from  the  heart  to 
the  different  parts  of  the  body,  and  returns  again  from 
these  parts  to  the  heart.  They  are  to  be  found,  in  varying 
proportions,  in  almost  every  part  of  the  body,  and  seem  to 
enter  into  its  texture. 

The  tubes,  which  carry  blood  from  the  heart,  are  more 
substantial  and  more  elastic  than  those  through  which  it 
returns  to  the  heart.  They  are  generally  found  empty 
after  death;  and,  therefore,  were  called  Arteries  by  the 
ancient  anatomists,  who  supposed  that  they  carried  air, 
and  not  blood. 

The  tubes  which  return  the  blood  to  the  heart  are 
denominated  Feins.  They  are  less  substantial  and  less 
elastic  than  arteries,  and  are  generally  full  of  blood  in  the 
dead  subject. 

There  are  two  great  arteries,  from  which  all  the  other 
arterial  vessels  of  the  body  are  derived.  They  are  very 
justly  compared  to  the  trunks  of  trees,  and  the  smaller 


225 


The  Bloodvessels  in  general. 

vessels  to  their  branches.  One  of  these  great  arteries, 
called  the  Aorta,  carries  blood  to  every  part  of  the  body. 
The  other  great  vessel,  called  the  Pulmonary  Artery , 
carries  blood  exclusively  to  the  lungs. 

The  veins  which  correspond  to  the  branches  of  the 
Aorta , unite  to  each  other,  so  as  to  form  two  great  trunks 
that  proceed  to  the  heart.  One  of  these  trunks,  coming 
from  the  superior  parts  of  the  body,  is  called  the  Superior , 
or  Descending  Vena  Cava.  The  other,  which  comes  from 
the  lower  parts  of  the  body,  is  called  the  Inferior , or 
Ascending  Vena  Cava. 

The  veins  which  correspond  with  the  branches  of  the 
Pulmonary  Artery , and  return  to  the  heart  the  blood  of 
the  lungs,  are  four  in  number:  two  of  them  proceeding 
from  each  lung.  They  are  called  Pulmonary  Veins. 

In  many  of  the  veins  there  are  valves,  which  prevent 
the  blood  they  contain  from  moving  towards  the  surface 
and  extremities  of  the  body,  but  allow  it  to  pass  towards 
the  heart  without  impediment. 

From  the  construction  of  the  cavities  of  the  heart,  and 
the  position  of  the  valves  which  are  in  them;  as  well  as  the 
situation  of  the  valves  at  the  commencement  of  the  great 
arteries , and  the  above  mentioned  valves  of  the  veins,  it  is 
evident,  that  when  the  blood  circulates,  it  must  move  from 
the  heart,  through  the  aorta  and  its  branches,  to  the  differ- 
ent parts  of  the  body,  and  return  from  these  parts  through 
the  venae  cavae  to  the  heart;  that,  when  deposited  in  the 
heart  by  the  venae  cavae,  it  must  proceed  through  the  pul- 
monary artery  to  the  lungs,  and  return  from  the  lungs 
through  the  pulmonary  veins  to  the  heart,  in  order  to 
pass  again  from  that  organ  into  the  aorta. 

Vol.  II,  2 F 


226 


The  Bloodvessels  in  general. 

It  is  also  certain,  that  the  blood  is  forced  from  the 
heart  into  the  arteries,  by  the  contraction  of  the  muscular 
fibres  of  which  the  heart  is  composed;  and  that  the  blood- 
vessels likewise  perform  a part  in  the  circulation,  they 
propelling  the  blood  which  is  thus  thrown  into  them:  but 
their  action  appears  to  depend  upon  causes  of  a complex 
nature. 


227 


CHAPTER  I. 

OF  THE  GENERAL  STRUCTURE  AND  ARRANGEMENT  OF 
THE  BLOODVESSELS, 

SECTION  I. 

Of  the  Arteries . 

The  arteries  are  so  much  concerned  in  the  important 
function  of  the  circulation  of  the  blood,  that  every  cir- 
cumstance connected  with  them  is  very  interesting. 

They  are  composed  of  coats  or  tunics,  which  are  very 
elastic  and  strong,  and  which  are  also  very  thick.  In  con- 
sequence of  the  firmness  of  their  coats,  they  continue 
open,  after  their  contents  are  discharged,  like  hard  tubes. 
They  submit  to  great  dilatation,  and  elongation,  when 
fluids  are  forced  into  them,  and  return  to  their  former 
dimensions  when  the  distending  cause  is  withdrawn.  This 
elasticity  is  particularly  subservient  to  the  circulation  of 
the  blood.  It  admits  the  artery  to  distend  readily,  and 
receive  the  blood  which  is  thrown  into  it  by  the  contrac- 
tion of  the  heart.  It  also  produces  the  contraction  of  the 
artery;  which  takes  place  as  soon  as  the  action  of  the 
heart  ceases;  and  this  contraction  of  the  artery  necessarily 
forces  the  blood  forward,  as  the  valves  at  its  orifice  pre= 
vent  it  from  returning  to  the  heart. 

The  motion  of  the  artery,  which  is  so  easily  perceived 
by  the  touch,  and  in  many  instances  also  by  the  eye,  is 


228  Structure  of  the  Arteries . 

completely  explained  by  the  discharge  of  blood  into  the 
artery  front  the  heart,  and  by  the  elasticity  of  the  vessel, 
by  which  it  reacts  upon  the  blood.  In  some  cases  it  is  not 
simply  the  diameter  of  the  artery  which  is  enlarged,  but 
a portion  of  the  vessel  is  elongated;  and  this  elongation, 
by  producing  a curvature  of  it,  renders  its  motion  more 
visible. 

In  the  aorta,  and  probably  in  its  large  branches,  Elasti- 
city seems  to  be  the  principal  cause  of  the  continuance  of 
the  motion  which  is  originally  given  to  the  blood  by  the 
heart.  But  there  are  many  circumstances  connected  with 
the  smaller  vessels,  which  evince  that  they  exert  a power 
which  is  very  different  indeed  from  elasticity.  Thus  the 
application  of  local  stimulants  or  rubefacients,  and  of 
heat,  is  followed  by  an  increase  of  motion  in  the  arteries 
of  the  parts  to  which  they  are  applied.  Neither  of  these 
causes  could  produce  their  effect  by  the  influence  of 
elasticity:  but  the  effect  of  these  and  other  similar 
causes  is  uniformly  produced;  and  a power  of  inde- 
pendent motion,  or  Irritability , is  thus  proved  to  exist 
in  these  vessels,  and  seems  essentially  necessary  to  the 
circulation  of  the  blood. 

The  Structure  of  the  Arteries 

Is,  therefore,  a subject  of  importance,  and  has  received 
a considerable  degree  of  attention  from  anatomists. 

They  are  composed  of  a dense  elastic  substance,  of 
a whitish  colour.  Their  external  surface  is  rough,  and 
intimately  connected  with  the  cellular  membr.ane,  which 
every  where  surrounds  it  in  varying  quantities.  Inter- 
nally, they  are  lined  with  a thin  membrane,  which  is  very 
smooth  and  flexible,  and  is  also  very  elastic.  The  sub- 


229 


Structure  of  the  Arteries. 

stance  which  composes  the  artery,  and  is  situated  between 
the  cellular  investment  and  die  internal  membrane,  con- 
sists of  fibres,  which  are  nearly,  though  not  completely, 
circular,  but  so  arranged  as  to  constitute  a cylinder.  These 
fibres  may  be  separated  from  each  other  so  as  to  form 
laminte,  which  have  been  considered  as  different  coats  of 
the  arteries;  but  there  is  no  arrangement  of  them  which 
composes  regular  distinct  strata.  The  coats  of  arteries 
may,  therefore,  be  separated  into  a greater  or  smaller 
number  of  laminse,  according  to  the  thickness  of  these 
laminae. 

The  fibres  which  compose  these  laminae  appear  to  be 
united  to  each  other  in  a way  which  readily  allows  of 
their  separation,  at  the  same  time  that  they  form  a firm 
texture.  Although  arteries  thus  appear  essentially  different 
from  muscles  in  their  hardness  and  their  elasticity,  as 
well  as  in  their  general  texture,  they  are  considered,  by 
a great  majority  of  anatomists,  as  partaking  more  or 
less  of  a muscular  structure. 

In  the  human  subject  their  structure  is  very  difficult  of 
demonstration,  and  great  differences  exist  in  the  accounts 
which  are  given  of  it,  even  by  anatomists,  who  agree  in  the 
general  sentiment  that  the  arteries  are  muscular. 

Thus  Haller  believed  that  muscular  fibres  were  most 
abundant  in  the  large  arteries,  while  J.  Hunter  thought 
the  reverse. 

Hunter  appears  to  have  investigated  this  subject  with 
great  attention,  and  supposed  the  muscular  substance,  in 
the  composition  of  arteries,  to  be  interior,  and  the  elastic 
matter  exterior;  that  in  large  arteries  this  muscular  sub- 
stance is  very  small  in  quantity,  and  gradually  increases 
in  proportion  as  the  artery  diminishes  in  size.  He  however 


230  Question  respecting  the  muscularity  of  Arteries. 

observes,  that  he  never  could  discover  the  direction  of  the 
muscular  fibres.*  I 

When  the  great  talents  of  Mr.  Hunter,  as  an  anatomist, 
are  considered,  this  circumstance  cannot  fail  to  excite  a 
belief  that  the  existence  of  these  fibres  is  not  certain:  and 
if  to  this  be  added  the  fact,  that  even  the  red  coloured 
substance  of  the  arteries  is  elastic,  and  in  that  respect  differ- 
ent from  muscular  substance,  the  reasons  for  doubting 
must  be  increased. 

Bichat  appears  to  have  entertained  very  strong  doubts 
®n  the  subject;  but  he  stands  almost  alone;  for  a large 
number  both  of  the  preceding  and  cotemporary  anato- 
mists, seem  to  have  adopted  the  sentiment,  that  the  arte - 
ries  have  a muscular  structure. 

The  student  of  anatomy  can  very  easily  examine  this 
subject  himself,  by  separating  the  coats  of  arteries  into  dif- 
ferent laminae;  and  by  viewing  the  edges  of  the  transverse 
and  longitudinal  sections  of  those  vessels.  While  thus 
engaged  with  this  question,  he  will  read  with  great  advan- 
tage what  has  been  written  upon  it  by  Mr.  Hunter,  in  his 
Treatise  on  the  Blood,  &c.  See  chapter  second,  section  3. 
Bichat  ought  also  to  be  read  upon  this  subject,  which  he 
has  discussed  in  his  AnatomieGenerale — System  Vasculaire 
a Sang  Rouge , article  Troisieme , &c.  and  also  in  his 
Traite  des  Membranes , article  Sixieme. 

The  belief  of  the  irritability  of  arteries  does  not,  how- 
ever, rest  upon  the  appearance  of  their  fibres. 

1.  It  is  asserted  by  very  respectable  authors,!  that  they 
have  been  made  to  contract  by  the  application  of  mecha- 

* Treatise  on  the  Blood,  &c.  Vol.  I.  p.  113.  Bradford’s  edition. 

f See  Soemmering-  on  the  Structure  of  the  Human  Body,  Vol.  IV. 
German  edition.  D;\  Jones  on  the  Process  employed  by  Nature  for 
suppressing  Haemorrhage,  &r 


Proofs  of  the  Irritability  of  the  Arteries.  231 

meal  and  of  chemical  irritation,  and  also  of  the  electric 
and  galvanic  power. 

2.  A partial  or  local  action  of  arteries  is  often  pro- 
duced by  the  local  application  of  heat  and  rubefacients,  as 
has  been  already  observed. 

3.  Arterial  action  is  often  suspended  in  a particular 
part  by  the  application  of  cold.  It  has  also  been  observed 
that  the  arteries  have  for  a short  time  ceased  to  pulsate 
in  cases  of  extreme  contusion  and  laceration  of  the 
limbs.f 

4.  When  arteries  are  divided  transversely  in  living 
animals,  they  often  contract  so  as  to  close  completely  the 
orifice  made  by  the  division. 

5.  In  a horse  bled  to  death,  it  was  ascertained  by  Mr. 
Hunter,  that  the  transverse  diameter  of  the  arteries 
was  diminished  to  a degree  that  could  not  be  explained 
by  their  elasticity.  He  also  found  that,  after  death,  the 
arteries,  especially  those  of  the  smaller  size,  are  generally 
in  a state  of  contraction,  which  is  greater  than  can  be 
explained  by  their  elasticity:  for  if  they  are  distended 
mechanically,  they  do  not  contract  again  to  their  former 
size,  but  continue  of  a larger  diameter  than  they  were 
before  the  distention;  although  their  elasticity  may  act  so 
as  to  restore  a very  considerable  degree  of  the  contraction 
observed  at  death. 

The  contraction,  which  is  thus  done  away  by  disten- 
tion, Mr.  Hunter  supposed  to  have  been  produced  by 
muscular  fibres:  for,  if  it  had  been  dependent  on  elastici- 
ty, it  must  have  reappeared  when  the  distending  power 
was  withdrawn. 

t This  local  suspension  of  arterial  motion  by  cold,  &c.,  applied 
locally,  is  very  difficult  to  explain;  as  the  action  of  the  heart  and  the 
elasticity  of  the  arteries  appear  sufficient  to  account  for  the  pulsation 
of  the  large  arteries. 


232  Proofs  of  the  Irritability  of  the  Arteries. 

It  therefore  seems  certain,  that  the  arteries  have  a 
power  of  contraction  different  from  that  which  depends 
upon  elasticity:  but  whether  this  depends  upon  muscular 
fibres  superadded  to  them,  or  upon  an  irritable  quality 
in  the  ordinary  elastic  fibres  of  bloodvessels,  is  a question 
which  is  not  perhaps  completely  decided. 

The  motion  of  the  blood  in  the  arteries  appears  to 
depend, 

1st,  Upon  the  impulse  given  to  it  by  the  action  of 
the  heart. 

2dly,  Upon  the  elasticity  of  the  arteries,  in  consequence 
of  which  they  first  give  way  to  the  blood  impelled  into 
them,  and  then  react  upon  it;  and 

3dly,  Upon  the  power  of  contraction  in  the  arteries,  or 
their  irritability. 

In  the  larger  arteries  the  blood  seems  to  move  as  it 
would  through  an  inanimate  elastic  tube,  in  consequence 
of  the  impulse  given  by  the  heart,  and  kept  up  by  the 
arteries  themselves.  In  the  smaller  vessels  it  seems  pro- 
bable that  the  motion  of  the  blood  depends  in  a consi- 
derable degree  upon  the  contraction  which  arises  from 
their  irritability. 

The  obvious  effect  of  the  elasticity  of  the  arteries  is  to 
resist  distention  and  elongation,  and  to  contract  the  artery 
to  its  natural  state,  when  the  distending  or  elongating 
cause  ceases  to  act.  But  it  must  also  resist  the  contraction 
induced  by  the  muscular  fibres,  and  restore  the  artery  to 
its  natural  size  when  the  muscular  fibres  cease  to  act  after 
contracting  it,  as  has  been  observed  by  Mr.  Hunter. 

It  seems  probable  that  all  the  fibres  of  which  the  artery 
consists  are  nearly  but  not  completely  circular;  for  it 
is  not  certain  that  there  are  any  longitudinal  fibres  in  the 
structure  of  an  artery. 


General  Observations  on  the  Arteries . .233 

The  internal  coat  of  these  vessels  is  very  smooth,  but 
extremely  dense  and  firm;  and  seems  to  be  rendered 
moist  and  flexible  by  an  exudation  on  its  surface.  It 
adheres  very  closely  to  the  contiguous  fibres  of  the  coat 
exterior  to  it,  but  may  be  very  readily  peeled  off  from 
them.  It  is  of  a whitish  colour,  and,  like  the  fibrous 
structure  of  the  artery,  is  very  elastic.  Like  that  sub- 
stance also  it  is  easily  torn  or  broken,  and,  when  ligatures 
have  been  applied  to  arteries,  it  has  been  often  observed 
that  the  fibrous  structure  and  the  internal  coat  have  been 
separated,  while  this  external  cellular  coat  has  remained 
entire. 

The  arteries  are  supplied  with  their  proper  blood- 
vessels and  lymphatics.  It  is  to  be  observed,  that  the 
bloodvessels  are  not  derived  from  the  artery  on  which 
they  run,  but  from  the  contiguous  vessels. 

These  vessels  have  nerves  also,  which  are  rather  small  in 
size,  when  compared  with  those  which  go  to  other  parts. 

Arteries  appear  to  have  a cylindrical  form,  for  no 
diminution  of  diameter  is  observable  in  those  portions  of 
them  which  send  off  no  ramifications. 

When  an  artery  ramifies,  the  area  of  the  different 
branches  exceeds  considerably  that  of  the  main  trunk. 
Upon  this  principle  the  aorta  and  its  branches  have 
been  compared  to  a cone,  the  basis  of  which  is  formed 
by  the  branches,  and  the  apex  by  the  trunk. 

The  transverse  section  of  an  artery  is  circular. 

There  are  no  valves  in  the  arteries,  except  those  of  the 
orifices  of  the  aorta  and  the  pulmonary  artery,  at  the  heart. 
The  valves  of  the  pulmonary  artery  have  been  described  in 
the  35th  page  of  this  volume,  and  those  of  the  aorta  hav^ 
an  exact  resemblance  to  them,  but  are  rather  larger. 

Vol.  II.  2 0 


234  General  Observations  on  the  Arteries. 

The  course  of  the  arteries  throughout  the  body  is 
obviously  calculated  to  prevent  their  exposure  to  pressure, 
or  to  great  extension  from  the  flexure  of  the  articulations 
by  which  they  pass.  With  this  view  they  sometimes  pro- 
ceed in  a winding  direction;  and  when  they  pass  over 
parts  which  are  subject  to  great  distention  or  enlargement, 
as  the  cheeks,  they  often  meander;  and,  therefore,  their 
length  may  be  increased  by  straightening,  without  stretch- 
ing them. 

Their  course  appears  sometimes  to  have  been  calculated 
to  lessen  the  force  of  the  blood,  as  is  the  case  with  the 
Internal  Carotid  and  the  Vertebral  arteries. 

In  the  trunk  of  the  body  the  branches  of  arteries 
generally  form  obtuse  angles  with  the  trunks  from  which 
they  proceed.  In  the  limbs  these  angles  are  acute. 

The  communication  of  arteries  with  each  other  is 
termed  Anastomosis.  In  some  instances,  two  branches 
which  proceed  in  a course  nearly  similar,  unite  with 
an  acute  angle,  and  form  one  common  trunk.  Sometimes, 
a transverse  branch  runs  from  one  to  the  other,  so  as 
to  form  a right  angle  with  each.  In  other  cases,  the  two 
anastomosing  branches  form  an  arch,  or  portion  of  a 
circle,  from  which  many  branches  go  off. 

By  successive  ramifications,  arteries  gradually  diminish 
in  size,  until  they  are  finally  extremely  small. 

The  smallest  arteries  do  not  carry  red  blood,  their 
diameters  being  smaller  than  those  of  the  red  particles 
of  that  fluid:  the  serous  or  aqueous  part  of  the  blood  can, 
therefore,  only  pass  through  them. 

Many  of  the  arteries  which  carry  red  blood,  and  of  the 
last  mentioned  serous  arteries  terminate  in  veins,  which 
are,  in  some  respects,  a continuation  of  the  tube  reflected 
backwards. 


General  Observations  on  the  Veins.  235 

They  likewise  terminate  in  exhalent  vessels,  which  open 
upon  the  external  surface,  and  upon  the  various  internal 
surfaces  of  the  body.  The  secretory  vessels  of  glands  are 
likewise  the  termination  of  many  arteries. 

SECTION  II. 

Of  the  Veins. 

THESE  tubes,  which  return  to  the  heart  the  blood 
carried  from  it  by  the  arteries,  are  more  numerous  than 
the  arteries,  and  often  are  larger  in  diameter. 

They  generally  accompany  the  arteries,  and  very  often 
two  veins  are  found  with  one  artery. 

In  addition  to  these  last  mentioned  veins,  which  may 
be  called  deep-seated , there  are  many  subcutaneous  veins 
which  appear  on  almost  every  part  of  the  surface  of  the 
body. 

The  capacity  of  all  the  veins  is  therefore  much  greater 
than  that  of  all  the  arteries. 

Those  subcutaneous  veins,  which  are  of  considerable 
size,  communicate  very  freely  with  each  other,  and  also 
with  the  deep-seated  veins. 

The  trunks  of  the  veins,  in  those  places  where  no 
branches  go  off,  are  generally  cylindrical.  There  are 
however  some  exceptions,  in  which  these  vessels  are  irre- 
gularly dilated,  as  sometimes  happens  in  the  case  of  the 
internal  jugular  vein.  It  is,  however,  not  easy  to  determine 
from  the  appearance  of  veins  injected  after  death,  respect- 
ing their  situation  during  life,  as  their  coats  are  very7 
yielding;  and  it  is  very  probable  that  they  are,  therefore, 
preternaturallv  dilated  by  the  injection. 

Veins , directly  or  indirectly,  originate  from  the  termi- 
nation of  arteries:  but  they  do  not  pulsate  as  the  arteries 


236 


Coats  of  Veins.  Valves  of  Veins. 

do,  because  the  impulse  given  to  the  blood  by  the  heart 
is  very  much  diminished  in  consequence  of  the  great 
diminution  of  the  size  of  the  vessels  through  which  the 
blood  has  passed. 

In  some  cases,  however,  when  blood  flows  from  ail 
opened  vein;  the  extent  of  its  projection  is  alternately 
increased  and  diminished,  in  quick  succession,  as  if  it  were 
influenced  by  the  pulsation  of  the  heart. 

The  Coats  of  Veins  differ  considerably  from  those  of 
Arteries , — for  they  are  thinner , and  so  much  less  firm , 
that  veins,  unlike  arteries,  collapse  when  they  are  empty. 
They  consist  of  a dense  elastic  substance,  the  fibres  of 
which  are  much  less  distinct  than  those  of  arteries,  but 
some  of  them  are  to  be  seen  in  a longitudinal  direction. 
These  fibres  can  be  7nade  to  contract  by  local  irritation ; 
for  if  a vein  be  laid  bare  in  a living  animal,  and  then 
punctured,  it  will  often  contract  so  as  to  diminish  its 
diameter  very  considerably,  although  no  blood  shall  have 
escaped  from  the  punctures. 

Next  to  the  elastic  substance  is  the  internal  coat,  which 
is  smooth  and  polished.  It  is  separated  from  the  substance 
exterior  to  it  with  difficulty,  although  it  may  be  taken  from 
it  very  easily  in  the  vena  cava. 

This  internal  coat  is  more  distendible  than  the  internal 
coat  of  arteries,  and  is  not,  like  the  latter,  disposed  to  os- 
sification. It  is  frequently  so  arranged  as  to  form  valves, 
which  are  plaits  or  folds,  of  a semilunar  form,  that  project 
from  the  surfaces  into  the  cavities  of  these  vessels. 

Two  of  these  valves  are  generally  placed  opposite  to 
each  other;  and,  when  raised  up,  they  form  a septum 
in  the  cylindrical  cavity  of  the  vessel.  The  septum,  thus 
composed,  is  concave  towards  the  heart. 


237 


Colour  of  the  Blood  in  the  Feins. 

The  valves  have  a great  effect  in  preventing  the  contents 
of  the  veins  from  moving  in  a retrograde  course:  they, 
therefore,  necessarily  modifv  the  effects  of  lateral  pressure, 
in  such  a manner,  that  it  propels  the  blood  forward,  or 
to  the  heart. 

These  valves  are  generally  found  in  the  veins  of  the 
muscular  parts  of  the  body,  especially  in  those  of  the 
extremities.  They  are  not  found  in  those  veins  which  are 
in  the  cavities  of  the  body,  nor  in  the  internal  jugulars. — - 
They  are  placed  at  unequal  distances  from  each  other. 

The  coats  of  the  veins  are  somewhat  transparent;  and, 
therefore,  those  veins  which  are  subcutaneous  have  a 
bluish  aspect,  which  is  derived  from  the  colour  of  the 
blood  they  contain. 

The  colour  of  the  blood  in  the  veins  is  different  from 
that  in  the  arteries,  being  of  a darker  red. 

The  situation  and  arrangement  of  the  large  trunks  of 
veins  is  much  alike  in  different  subjects;  but  the  branches, 
especially  those  which  are  subcutaneous,  are  very  variable 
in  their  situations. 


238 


CHAPTER  II. 

1 PARTICULAR  ACCOUNT  OF  THE  DISTRIBUTION  OF  THE 
ARTERIES. 


SECTION  I. 


Of  the  AORTA, 

Or  the  Great  Trunk  of  the  Arterial  System. 

When  the  heart  is  in  its  natural  position,  the  right  ven- 
tricle is  nearly  anterior  to  the  left;  and,  therefore,  the 
AORTA,  where  it  originates  from  the  left  ventricle,  is 
behind  the  pulmonary  artery,  and  covered  by  it.  Its  first 
direction  is  so  oblique  towards  the  right  side  of  the  body, 
that  it  crosses  the  pulmonary  artery  behind,  and  appears  on 
the  right  side  of  it.  It  has  scarcely  assumed  this  position 
before  its  course  alters,  for  it  then  proceeds  obliquely  back- 
wards, and  to  the  left;  so  as  to  form  a large  curve  or  arch, 
which  extends  to  the  left  of  the  spine. 

The  position  of  this  curve  or  arch  is  so  oblique,  with 
respect  to  the  body,  that  the  cord  or  diameter  of  it,  if  it 
were  extended  anteriorly  and  posteriorly,  would  strike  the 
cartilage  of  the  second  or  third  right  rib  about  the  middle 
of  its  length,  and  the  left  rib  near  the  head.  In  consequence 
of  this  position  of  the  curve,  the  AORTA  crosses  oVer 
the  right  branch  of  the  pulmonary  artery,  and  the  left 
branch  of  the  windpipe:  and  assumes  a situation,  in  front, 
and  to  the  left  of  the  third  dorsal  vertebra:  from  this 
situation  it  proceeds  downwards;  in  front,  but  rather  on 
the  left  side  of  the  spine,  and  in  contact  with  that  column. 


Situation  of  the  Aorta  in  the  Thorax  and  Abdomen.  239 

The  AORTA,  as  well  as  the  Pulmonary  Artery,  for  a 
small  distance  from  the  heart,  is  invested  by  the  peri- 
cardium; and,  when  that  sac  is  opened,  appears  to  be 
contained  in  it. 

After  crossing  the  right  branch  of  the  Pulmonary 
Artery , a ligament  is  inserted  into  it,  which  proceeds  from 
the  main  trunk  of  the  pulmonary  artery  at  its  division: 
this  ligament  was  the  Canalis  Arteriosus  in  the  fcetus. 

As  the  AORTA  proceeds  down  the  spine,  it  is  situated 
between  the  two  laminte  of  the  mediastinum,  and  in  con- 
tact with  the  left  lamina,  through  which  it  may  be  seen.  It 
descends  between  the  crura  of  the  diaphragm,  in  a vacuity 
which  is  sufficiently  large  to  admit  of  its  passage  without 
pressure  from  the  surrounding  parts,  and  is  still  in  contact 
with  the  anterior  surface  of  the  spine,  but  rather  to  the 
left  of  the  middle  of  it.  It  continues  this  course  along  the 
spine  until  it  arrives  at  the  cartilaginous  substance  between 
the  fourth  and  fifth  lumbar  vertebrae,  when  it  divides  into 
two  great  branches  of  equal  size,  which  form  an  acute 
angle  with  each  other.  These  are  denominated  the  COM- 
MON, or  PRIMITIVE  ILIAC  Arteries. 

From  the  AORTA  in  this  course  are  sent  off  the  arteries 
which  are  distributed  to  all  the  parts  of  the  body  for  their 
nourishment  and  animation. 

From  the  curve  proceed  the  great  branches  which  sup- 
ply the  heart,  the  head,  the  upper  extremities,  and  part 
of  the  thorax.  Between  the  curve  and  the  great  primitive 
iliac  arteries,  the  AORTA  sends  off  those  branches  which 
supply  the  viscera  contained  in  the  cavities  of  the  thorax 
and  abdomen,*  and  part  of  the  trunk  of  the  body.  The 
great  ILIAC  branches  of  the  AORTA  are  divided  into 

* It  ought  to  be  observed  here,  that  the  viscera  in  the  lower  part  of 
'he  pelvis  receive  some  branches  from  the  internal  iliac  arteries. 


240  Origin  cf  the  Subclavian  and  Carotid  Arteries - 

smaller  arteries,  which  supply  the  whole  of  the  lower 
extremities  and  some  of  the  viscera  of  the  pelvis. 

SECTION  II. 

Of  the  Branches  which  go  off  from  the  arch  of  the 

AORTA. 

THE  proper  arteries  of  the  heart,  denominated  coro- 
nary arteries,  proceed  from  the  AORTA  so  near  to 
the  heart  that  their  orifices  are  covered  by  the  semilunar 
valves,  when  those  valves  are  pressed  against  the  sides  of 
the  artery.  These  arteries  have  been  described  in  the 
account  of  the  heart. — See  p.  58. 

The  arteries  of  the  head  and  of  the  upper  extremities 
proceed  from  the  upper  part  of  the  curve  in  the  following- 
manner. 

A large  trunk,  called  ARTERIA  INNOMINATA, 
goes  off  first.  This  is  more  than  sixteen  lines  in  length, 
when  it  divides  into  two  branches:  one  of  which  supplies 
the  right  side  of  the  head,  and  is  denominated  the  RIGHT 
CAROTID:  the  other  proceeds  to  the  right  arm,  and  from 
its  course  under  the  clavicle,  is  called,  at  first,  the  RIGHT 
SUBCLAVIAN.  Almost  in  contact  with  the  firsttrunk, 
another  artery  goes  off,  which  proceeds  to  the  left  side  of 
the  head,  and  is  called  the  LEFT  CAROTID.  Very 
near  to  this,  arises  the  third  artery,  which  proceeds  to 
the  left  arm,  and  is  denominated  the  LEFT  SUBCLA- 
VIAN. From  these  great  branches  originate  the  blood- 
vessels, which  are  spent  upon  the  head  and  neck  and 
the  upper  extremities. 

As  these  arteries  arise  from  the  curve  of  the  AORTA, 
they  are  situated  obliquely  with  respect  to  each  other, 


Situation  of  the  Common  Carotid  Arteries.  241 

The  ARTERIA  INNOMINATA  is  not  only  to  the 
right,  but  it  is  also  anterior  to  the  two  others:  and  the 
LEFT  SUBCLAVIAN  is  posterior,  as  well  as  to  the 
left  of  the  LEFT  CAROTID  and  the  ARTERIA  IN- 
NOMINATA. 

THE  CAROTID  ARTERIES. 

The  two  carotid  arteries  above  mentioned  have  been 
denominated  COMMON  CAROTIDS,  to  distinguish 
them  from  their  first  ramifications,  which  are  called  IN- 
TERNAL and  EXTERNAL  CAROTIDS. 

THE  COMMON  CAROTIDS 
Proceed  towards  the  head  on  each  side  of  the  trachea:  at 
first  they  diverge,  but  they  soon  become  nearly  parallel  to 
each  other,  and  continue  so  until  they  have  ascended  as  high 
as  the  upper  edge  of  the  thyroid  cartilage,  when  they  divide 
into  the  INTERNAL  and  EXTERNAL  CAROTIDS. 

These  arteries  are  at  first  very  near  each  other,  and 
rather  in  front  of  the  trachea;  they  gradually  diverge  and 
pass  backwards  and  outwards  on  the  sides  of  it,  and  of  the 
(esophagus,  until  they  have  arrived  at  the  larynx.  In  the 
lower  part  of  the  neck  they  are  covered  by  the  sterno  mas- 
toidei,  the  sterno  hyoidei,  and  thyroidei,  as  well  as  by  the 
platysma  myoidei  muscles.  Above,  their  situation  is  more 
superficial;  and  they  are  immediately  under  the  platysma 
myoides. 

On  the  inside,  they  are  very  near  the  trachea  and  la- 
rynx, and  the  oesophagus;  on  the  outside,  and  rather  ante- 
rior to  them,  are  the  internal  jugular  veins;  and  behind, 
on  each  side,  are  two  important  nerves  called  the  inter- 
costal and  thenar  vagum.  These  bloodvessels  and  nerve's 
are  surrounded  by  absorbent  vessels. 

Vol.  II.  2 H 


242  General  Account  of  the 

The  COMMON  CAROTID  ARTERIES  send  off 
no  branches  from  their  origin  to  their  bifurcation;  and 
they  appear  to  preserve  the  same  diameter  throughout 
their  whole  extent.  In  some  few  instances  the  right  caro- 
tid has  been  found  larger  than  the  left.  The  external  and 
internal  branches  into  which  they  divide,  are  nearly  equal 
in  the  adult;  but  it  is  supposed  that  the  internal  is  the  largest 
during  infancy.  The  relative  position  of  these  branches 
is  also  different  at  the  commencement  from  what  it  is 
afterwards.  The  INTERNAL  CAROTID  forms  a curve 
which  projects  outwardly,  so  as  to  be  exterior  to  the 
EXTERNAL  CAROTID , while  this  last  proceeds  up- 
wards, and  rather  backwards. 

THE  EXTERNAL  CAROTID  ARTERY 
May  be  considered  as  extending  from  its  commence- 
ment, which  is  on  a line  with  the  superior  margin  of  the 
thyroid  cartilage,  to  the  neck  of  the  condyle  of  the  lower 
jaw,  or  near  it. 

At  first  it  is  superficial;  but  as  it  proceeds  upwards  it 
becomes  deepseated;  and  passing  under  the  digastric  and 
stylo  hyoidei  muscles,  and  the  ninth  pair  of  nerves,  is  co- 
vered by  the  Parotid  Gland.  After  this,  it  again  becomes 
superficial;  for  the  temporal  artery,  which  may  be  regarded 
as  the  continuation  of  the  external  carotid,  passes  over  the 
zygomatic  process  of  the  temporal  bone. 

As  the  external  carotid  supplies  with  blood  the  upper 
part  of  the  neck  and  throat,  the  exterior  of  the  head  and 
face,  and  the  inside  of  the  mouth  and  nose;  its  branches 
must  necessarily  be  numerous,  and  must  pass  in  very  va- 
rious directions. 

Thus,  soon  after  its  commencement,  it  sends  off,  in  an 
anterior  direction,  three  large  branches;  viz.  to  the  upper 


External  Carotid  and  its  Branches.  243 

part  of  the  neck,  to  the  parts  within  the  lower  jaw,  and  to 
the  cheeks  and  lips.  These  are  denominated,  the  superior 
thyroid,  the  sublingual,  and  the  facial.  It  then  sends 
off  to  the  back  of  the  head  one  which  is  called  the  occipi- 
tal; and,  as  it  proceeds  upwards  near  the  condyle  of  the 
lower  jaw,  another  which  passes  internally,  behind  the  jaw, 
to  the  deepseated  parts  in  that  direction.  After  this,  it  forms 
the  temporal  artery,  which  supplies  the  forehead  and  cen- 
tral parts  of  the  cranium.  Besides  these  larger  branches,  the 
external  carotid  sends  off  two  which  are  smaller;  one  from 
near  the  origin  of  the  sublingual  artery,  which  is  spent 
principally  upon  the  pharynx  and  fauces,  and  is  called  the 
inferior  pharyngeal:  and  another,  while  it  is  involved 
with  the  parotid  gland,  which  goes  to  the  ear;  and  is  there- 
fore called  posterior  auris. 

These  arteries  are  distributed  in  the  following  manner. 

l.The  SUPERIOR  THYROID  BRANCH 

Comes  off  very  near  the  root  of  the  external  carotid, 
and  sometimes  from  the  common  trunk;  it  runs  obliquely 
downwards  and  forwards,  in  a meandering  course,  to  the 
thyroid  gland,  where  it  is  spent.  During  this  course  it 
sends  off  one  branch  to  the  parts  contiguous  to  the  os 
hyoides;  another  to  the  neighbourhood  of  the  larynx:  and 
a third  branch,  which  may  be  termed  Laryngeal , that 
passes  with  a small  nerve  derived  from  the  laryngeal 
branch  of  the  par  vagum,  either  between  the  os  hyoides 
and  thyroid  cartilage,  or  the  thyroid  and  cricoid  cartilages, 
to  the  interior  muscles  of  the  larynx;  and  finally  returns 
again  to  terminate  externally. 

While  in  the  thyroid  gland  this  artery  anastomoses  with 
the  inferior  thyroid,  and  also  with  its  fellow  on  the  oppo- 
site side. 


244 


Branches  of  the  External  Carotid. 


2.  The  lingual,  or  sublingual  branch, 

Goes  off  above  the  last  mentioned  artery,  and  very 
near  it;  but  in  a very  different  direction,  for  it  runs  up- 
wards and  forwards,  to  the  tongue.  In  this  course  it 
crosses  obliquely  the  os  hyoides,  and  is  commonly  within 
the  hyoglossus  muscle.  It  gives  off  branches  to  the  middle 
constrictors  of  the  pharynx,  and  to  the  muscles  contiguous 
to  the  tongue.  It  also  sends  off  a branch  which  penetrates 
to  the  back  of  the  tongue,  which  is  called,  from  its  situation, 
Dorsalis  Linguce.  At  the  anterior  margin  of  the  hyoglossus 
muscle  it  divides  into  two  branches,  one  of  which  passes 
to  the  sublingual  gland  and  the  adjacent  parts,  and  is 
thence  called  Sublingual;  while  the  other  branch,  the 
Ranina,  passes  by  the  side  of  the  genio  glossus  muscle  to 
the  apex  of  the  tongue. 

3.  The  facial,  or  external  maxillary, 

Runs  obliquely  upwards  and  forwards  under  the  ninth 
pair  of  nerves,  the  stylo  hyoideus  muscle  and  the  tendon  of 
the  digastric,  across  the  lower  jaw  and  cheek,  towards  the 
inner  corner  of  the  eye,  in  a serpentine  course.  Before  it 
crosses  the  jaw  it  sends  off  several  branches,  viz:  to  the 
pharynx,  the  tonsils,  the  inferior  maxillary  gland  and  the 
parts  contiguous  to  it.  It  also  sends  a branch  towards  the 
chin,  which  passes  between  the  mylo-hyoideus,  the  an- 
terior belly  of  the  digastric,  and  the  margin  of  the  lower 
jaw:  and  some  of  its  branches  continue  to  the  muscles  of 
the  under  lip.  This  branch  is  called  the  Submental. 

This  artery  then  passes  round  the  basis  or  inferior  edge 
of  the  lower  jaw,  very  near  the  anterior  margin  of  the  mas- 
seter  muscle,  and  is  so  superficial  that  its  pulsations  can 
be  readily  perceived.  After  this  turn,  its  course  is  obliquely 


245 


Branches  of  the  External  Carotid. 

upwards  and  forwards.  Near  the  basis  of  the  jaw  it  sends 
off  a branch  to  the  masseter,  which  anastomoses  with  small 
branches  from  the  temporal;  and  another  which  passes 
superficially  to  the  under  lip  and  contiguous  parts  of  the 
cheeks.  This  last  is  called  the  Inferior  Labial. 

After  the  artery  has  passed  as  high  as  the  teeth  in  the 
lower  jaw,  it  divides  into  two  branches;  which  go,  one  to 
the  under,  and  the  other  to  the  upper  lip:  that  to  the  upper 
lip  is  largest.  These  branches  are  called  Coronary . 

The  Coronary  Artery  of  the  lower  lip  passes  under  the 
muscles  called  Depressor  Anguli  Oris,  and  Orbicularis 
Oris , into  the  substance  of  the  lip,  and  anastomoses  with 
its  fellow  of  the  opposite  side. 

The  Coronary  Artery  of  the  upper  lip  passes  under  the 
zygomaticus  major  and  the  orbicularis,  and  very  near  the 
margin  of  the  upper  lip  internally.  It  also  anastomoses 
freely  with  its  fellow  on  the  opposite  side.  These  anasto- 
moses are  frequently  so  considerable  that  the  arteries  on 
one  side  can  be  well  filled  by  injecting  those  of  the  other. 
The  coronary  branches,  as  well  as  the  main  trunk  of  the 
facial  artery,  observe  a serpentine  or  tortuous  course;  in 
consequence  of  which  they  admit  of  the  motions  of  the 
cheeks  and  lips,  which  they  would  greatly  impede  if  they 
were  straight. 

From  the  upper  coronary  artery  a branch  continues  in 
the  direction  of  the  main  trunk  of  the  facial  artery,  by  the 
side  of  the  nose,  which  extends  upwards,  sending  off 
small  branches  in  its  course,  and  finally  terminates  about 
the  internal  angle  of  the  eye  and  the  forehead. 

4.  The  INFERIOR  PHARYNGEAL 
Is  a very  small  artery;  it  arises  posteriorly  from  the 
external  carotid,  opposite  to  the  origin  of  the  sublingual, 


246  Branches  of  the  External  Carotid. 

and  passes  upwards  to  the  basis  of  the  cranium.  In  this 
course  it  sends  several  branches  to  the  pharynx,  and  to  the 
deep  seated  parts  immediately  contiguous. 

It  also  sends  branches  to  the  first  ganglion  of  the  inter- 
costal nerve,  to  the  par  vagum,  and  to  the  lymphatic  glands 
of  the  neck;  and  finally  it  enters  the  cavity  of  the  cranium 
by  the  posterior  foramen  lacerum. 

In  some  cases  it  also  sends  a small  branch  through  the 
anterior  foramen  lacerum. 

5.  The  OCCIPITAL  ARTERY 

Arises  from  the  posterior  side  of  the  external  carotid, 
nearly  opposite  to  the  facial,  but  sometimes  higher  up; 
it  ascends  obliquely,  and  passes  to  the  back  part  of  the 
cranium,  between  the  transverse  process  of  the  atlas  and 
the  mastoid  process  of  the  temporal  bone. 

In  this  course  it  passes  over  the  internal  jugular  vein 
and  the  eighth  pair  of  nerves,  and  under  the  posterior  part 
of  the  digastric  muscle;  it  lies  very  near  to  the  base  of  the 
mastoid  process,  and  under  the  muscles  which  are  inserted 
into  it.  After  emerging  from  these  muscles,  it  runs  super- 
ficially upon  the  occiput,  dividing  into  branches  which  ex- 
tend to  those  of  the  temporal  artery. 

The  occipital  artery  sends  off  branches  to  the 
muscles  which  are  contiguous  to  it,  and  to  the  glands 
of  the  neck. 

It  also  gives  off  the  following  branches:  One  called  the 
Meningeal , which  passes  through  the  posterior  foramen 
lacerum  to  the  under  and  back  part  of  the  dura  mater: 
one  to  the  exterior  parts  of  the  ear:  another  which  passes 
downwards,  and  is  spent  upon  the  complexus,  trachelo 
mastoideus,  and  other  muscles  of  the  neck:  and  several 
smaller  arteries. 


Branches  of  the  External  Carotid.  247 

The  artery  next  to  be  described,  is  sometimes  sent  off 
by  the  occipital  artery. 

6.  The  posterior  auricular,  or  stylo  mastoid 

ARTERY, 

When  it  arises  from  the  external  carotid,  comes  off 
posteriorly  from  the  artery,  where  it  is  involved  with 
the  parotid  gland,  and  passes  backwards  between  the 
meatus  auditorius  externus  and  the  mastoid  process.  It 
then  ascends,  in  a curved  direction,  and  terminates  behind 
the  ear. 

In  this  course  it  sends  off  small  branches  to  the  parotid 
gland,  and  to  the  digastric  and  sterno  mastoid  muscles. 
Sometimes  a distinct  branch,  which  is  particularly  visible 
in  children,  passes  through  an  aperture  in  the  meatus  au- 
ditorius externus,  and  is  spent  on  its  internal  surface. 

It  also  sends  off  a branch  which  enters  into  the  Stylo 
mastoid  Foramen , and  supplies  small  vessels  to  the  raem- 
brana  tympani  and  the  lining  membrane  of  the  cavity  of 
the  tympanum;  to  the  mastoid  cells;  to  the  muscle  of  the 
stapes,  and  to  the  external  semicircular  canal.  One  of  these 
vessels  anastomoses,  in  the  upper  and  posterior  part  of  the 
cavity  of  the  tympanum,  with  a small  twig-  derived  from 
the  artery  of  the  dura  mater.  When  it  has  arrived  behind 
the  ear,  the  Posterior  Auricular  Artery  terminates  upon 
the  external  ear  and  the  parts  contiguous  to  it. 

7.  The  INTERNAL  MAXILLARY  ARTERY* 

Arises  from  the  external  carotid  under  the  parotid  gland, 
at  a little  distance  below  the  neck  of  the  condyloid  process 

* The  general  situation  of  this  artery,  and  the  distribution  of  several 
of  its  most  important  branches,  cannot  be  understood  without  a know- 
ledge of  the  bones  through  which  they  pass.  The  student  of  surgferv 


248  The  Internal  Maxillary  Artery . 

of  the  lower  jaw,  and  extends  to  the  bottom  of  the  zy- 
gomatic fossa;  varying  its  direction  in  its  course.  It  is 
rather  larger  than  the  temporal. 

a.  It  first  sends  off  one  or  two  small  branches  to  the 
ear , and  a twig  which  penetrates  into  the  cavity  of  the 
tympanum  by  the  glenoid  fissure. 

b.  It  also  sends  off  a small  artery  called  the  Lesser  Me- 
ningeal, which  passes  upwards,  and  after  giving  branches 
to  the  external  pterygoid  and  the  muscles  of  the  palate, 
passes  through  the  foramen  ovale,  and  is  spent  upon  the 
dura  mater  about  the  sella  turcica. 

c.  It  then  sends  off  one  of  its  largest  branches,  the 
Great  or  Middle  Artery  of  the  Dura  Mater , which  passes 
in  a straight  direction  to  the  foramen  spinale,  by  which  it 
enters  into  the  cavity  of  the  cranium. 

This  artery  ramifies  largely  on  the  dura  mater,  and 
makes  those  arborescent  impressions  which  are  so  visible 
in  the  parietal  bone.  It  generally  divides  into  two  great 
branches:  the  anterior,  which  is  the  largest,  passes  over 
the  anterior  and  inferior  angle  of  the  parietal  bone:  the 
posterior  branch  soon  divides  into  many  ramifications, 
which  are  extended  laterally  and  posteriorly. 

It  furnishes  the  twig  which  passes  to  the  ear  by  the  hia- 
tus of  Fallopius,  and  anastomoses  with  the  small  branches 
of  the  stylo  mastoid  artery. 

It  also  supplies  some  other  small  vessels  which  pass  to 
the  cavity  of  the  tympanum  by  small  foramina  near  the 

will  therefore  derive  benefit  from  a re-examination  of  these  bones,  and 
of  the  zygomatic  fossa,  &c.  when  he  studies  this  artery.  (See  Vol.  I. 
page  64.) — He  ought  to  be  well  acquainted  with  this  subject,  if  he 
should  undertake  the  management  of  necrosis,  of  the  jaw  bones;  or  of 
those  fungous  tumours,  which  sometimes  originate  in  the  antrum 
maxillare;  as  well  as  of  several  other  complaints. 


The  Internal  Maxillary  Artery.  249 

junction  of  the  squamous  and  petrous  portions  of  the 
temporal  bone. 

D.  The  next  branch  sent  off  by  the  internal  maxillary 
leaves  it  about  an  inch  from  its  origin,  and  is  called  the 
Inferior  Maxillary.  It  passes  between  the  internal  ptery- 
goid muscle  and  the  bone,  and  after  giving  small  branches 
to  the  contiguous  muscles,  enters  the  canal  in  the  lower  jaw, 
in  company  with  the  nerve.  This  canal  has  a very  free 
communication  with  the  cellular  structure  of  the  jaw,  and 
the  artery  in  its  progress  along  it  sends  branches  to  the 
respective  teeth  and  the  bone.  At  the  anterior  maxillary 
foramen,  this  artery  sends  off  a considerable  branch,  which 
passes  out  and  anastomoses  with  the  vessels  on  the  chin, 
while  another  branch  passes  forward  and  supplies  the  ca- 
nine and  incisor  teeth  and  the  bone  contiguous  to  them. 

Sometimes  the  inferior  maxillary  artery  divides  into 
two  branches  before  it  has  arrived  at  this  foramen.  In  this 
case,  one  of  the  arteries  passes  out  of  the  foramen,  while 
the  other  continues  to  the  symphysis. 

E.  Two  branches  pass  off  to  the  temporal  muscle,  which 
originate  at  a small  distance  from  each  other:  one  of  them 
passes  upwards  on  the  tendon  of  the  temporal  muscle;  the 
other  arises  near  the  tuberosity  of  the  upper  maxillary 
bone:  they  are  called  the  exterior  deep , and  the  interior 
deep  temporal  artery.  They  are  both  spent  upon  the  tem* 
poral  muscle;  but  the  interior  branch  sends  a small  twig 
into  the  orbit  of  the  eye. 

s.  There  are  some  small  branches  which  pass  to  the 
Pterygoid  Muscles  and  to  the  Masseter , which  arise  either 
from  the  internal  maxillary  artery,  or  from  the  anterior 
deep  temporal.  They  are  generally  small,  and  often  irre- 
gular. 

VoL.  II.  2 I 


250  The  Internal  Maxillary  Artery: 

G.  An  artery,  particularly  appropriated  to  the  cheek, 
perforates  the  buccinator  muscle  from  within  outwards, 
and  generally  terminates  on  the  buccinator,  the  zygomati- 
cus  major  and  the  muscles  of  the  lips.  This  Artery  of  the 
Cheek  is  very  irregular  in  its  origin,  sometimes  arising 
from  the  internal  maxillary,  sometimes  from  the  deep 
temporal,  and  sometimes  from  the  suborbitary,  or  from 
the  alveolar  artery,  to  be  immediately  described. 

H.  The  Alveolar  Artery , or  the  Artery  of  the  Upper 
farv,  arises  generally  from  the  internal  maxillary,  but 
sometimes  from  one  of  its  branches.  It  winds  round  the 
tuberosity  of  the  upper  jaw,  and  sends  branches  to  the 
buccinator  muscle,  to  the  bone  and  the  gums,  to  the  an- 
trum highmorianum,  and  some  of  the  molar  teeth:  and 
also  to  the  teeth  generally,  by  means  of  a canal  which  is 
analogous  to  that  of  the  lower  jaw. 

i.  The  Infra-orbitar  Artery  arises  from  the  internal 
maxillary  in  the  zygomatic  fossa,  and  soon  enters  the 
infra  orbitary  canal,  through  which  it  passes  to  the  face, 
and  emerges  below  the  orbit  of  the  eye,  supplying  the 
muscles  in  the  vicinity,  and  anastomosing  with  the  small 
ramifications  of  the  two  last  described  arteries,  and  also 
of  the  facial  artery  and  the  ophthalmic. 

This  artery  in  its  course  sends  off  small  twigs  to  the  pe- 
riosteum, the  adipose  membrane,  and  the  muscles  in  the 
inferior  part  of  the  orbit,  and  also  to  the  great  maxillary 
sinus  or  antrum  highmorianum,  and  to  the  canine  and 
incisor  teeth. 

j.  The  Palato  Maxillary,  or  Superior  Palatine  Artery , 
arises  also  in  the  zygomatic  fossa,  and,  descending  behind 
the  upper  maxillary  bone,  enters  the  posterior  palatine  ca- 
nal. It  generally  forms  two  branches,  the  largest  of  which 
advances  forward,  supplying  the  palate  and  gums,  and 


Its  Termination  in  the  Nose.  Temporal  Artery.  251 

finally  sends  a twig  through  the  foramen  incisivum  to  the 
nose,  while  the  posterior  branch,  which  is  much  smaller, 
supplies  the  velum  pendulum  palati. 

K.  The  Pterygo  Palatine , or  Superior  Pharyngeal , is 
a small  vessel,  which  sometimes  arises  from  the  artery 
next  to  be  mentioned.  It  is  spent  upon  the  upper  part  of 
the  pharynx,  and  a branch  passes  through  the  pterygo  pala- 
tine foramen,  which  is  spent  upon  the  arch  of  the  palate 
and  the  contiguous  parts. 

L.  The  internal  maxillary  at  length  terminates  in 
the  Spheno- Palatine , or  Large  Nasal  Artery , which  passes 
through  the  spheno-palatine  foramen  to  the  back  part  of  the 
nose.  This  artery  sometimes  separates  into  two  branches 
before  it  enters  the  foramen;  sometimes  it  enters  singly, 
and  divides  into  two  branches  soon  after;  one  of  them 
is  spread  upon'  the  septum,  and  the  other  upon  the  ex- 
ternal side  of  the  nose;  each  of  these  branches  ramifies 
very  minutely  upon  the  Schneiderian  membrane  and  its 
processes  in  the  different  sinuses,  and  also  in  the  ethmoidal 
cells. 

8.  The  TEMPORAL  ARTERY 

Is  considered  as  the  continuation  of  the  external  carotid, 
because  it  preserves  the  direction  of  the  main  trunk,  al- 
though the  internal  maxillary  is  larger. 

After  parting  with  the  internal  maxillary  it  projects  out- 
wards; and  passing  between  the  Meatus  Auditorius  Ex- 
ternus  and  the  condyle  of  the  lower  jaw,  continues  up- 
wards, behind  the  root  of  the  zygomatic  process  of  the 
temporal  bone,  to  the  aponeurosis  of  the  temporal  muscle: 
on  the  outside  of  which,  immediately  under  the  integu- 
ments, it  divides  into  two  large  branches  denominated 
anterior  and  posterior. 


252  Temporal  Artery.  Internal  Carotid. 

Before  this  division  the  temporal  artery  sends  off  seve- 
ral branches  of  very  different  sizes. 

One,  which  is  considerable  in  size,  and  called  the  Trans- 
verse Facial  Branch , advances  forwards  across  the  neck  of 
the  condyle  of  the  lower  jaw,  and  giving  small  branches  to 
the  masseter,  runs  parallel  to  the  parotid  duct,  and  below 
it.  This  branch  is  spent  upon  the  muscles  of  the  face,  and 
anastomoses  with  the  other  vessels  of  that  part. 

The  temporal  gives  off  small  branches  to  the  parotid 
gland  and  to  the  articulation  of  the  jaw.  From  the  last 
mentioned  branch  small  twigs  pass  to  the  ear,  one  of  which 
enters  the  cavity  of  the  tympanum  by  the  glenoid  fissure. 

While  this  artery  is  on  a line  with  the  zygoma,  it  sends 
off  a branch  called  the  middle  temporal  artery , which  pene- 
trates the  aponeurosis  of  the  temporal  muscle,  and  rami- 
fies under  it  upon  the  muscle  in  an  anterior  direction. 

The  two  great  branches  of  the  temporal  artery  are  dis- 
tributed in  the  following  manner.  The  Anterior  passes  up 
in  a serpentine  direction  on  the  anterior  part  of  the  tem- 
ple, and  supplies  the  front  side  of  the  head,  and  the  upper 
part  of  the  forehead. 

The  Posterior  extends  upwards  and  backwards,  and 
supplies  the  scalp  on  the  lateral  and  middle  part  of  the 
cranium,  and  also  the  bone. 

Ramifications  from  each  of  these  branches  anastomose 
on  the  upper  part  of  the  cranium  with  those  of  its  fellow 
of  the  opposite  side.  The  anterior  branch  also  anastomo- 
ses on  the  forehead  with  the  facial  and  ophthalmic  artery; 
and  the  posterior  branch  with  the  occipital  artery  on  the 
back  part  of  the  head. 

THE  INTERNAL  CAROTID  ARTERY 

Is  sometimes  called  the  Artery  of  the  Brain.,  as  it  is 
almost  entirely  appropriated  to  that  viscus. 


Curvatures  of  the  Internal  Carotid.  253 

From  its  origin  to  the  commencement  of  its  ramifica- 
tions the  course  of  this  bloodvessel  is  peculiarly  tortuous. 
In  consequence  of  which,  the  force  of  the  blood  in  it  is 
greatly  diminished  before  it  arrives  at  the  brain. 

An  instance  of  this  curvature  occurs  immediately  after 
its  separation  from  the  external  carotid,  when  it  protrudes 
outwards  so  much  as  to  be  exterior  to  that  vessel;  after 
this,  it  ascends  to  the  carotid  canal,  and  in  its  course  is  in 
contact,  or  very  near  the  par  vagum  and  intercostal  nerves. 

The  carotid  canal  in  the  os  petrosum  is  by  no  means 
straight;  it  forms  a semicircular  curve,  forwards  and  in- 
wards; and  its  upper  portion,  which  is  nearly  horizontal, 
opens  obliquely  against  the  body  of  the  sphenoidal  bone  at 
a small  distance  from  it.  Therefore,  after  the  artery  has 
passed  through  the  canal,  it  must  turn  upwards  to  get 
fairly  into  the  cavity  of  the  cranium;  and  of  course,  its  di- 
rection while  in  the  canal,  forms  almost  a right  angle  with 
its  direction  before  it  enters,  and  after  it  emerges  from  it. 

In  consequence  of  this  curvature,  much  of  the  momen- 
tum of  the  blood  must  be  impressed  upon  the  cranium. 

After  the  artery  has  arrived  at  the  end  of  the  carotid 
canal,  and  has  turned  upwards  to  get  within  the  cavity  of 
the  cranium,  it  bends  forwards,  and  passes  nearly  in  a 
horizontal  direction,  through  the  cavernous  sinus  on  the 
side  of  the  sella  turcica,  to  the  anterior  clinoid  process; 
here  it  again  forms  a considerable  curve,  which  is  directly 
upwards,  and  then  it  perforates  the  dura  mater. 

These  curvatures  must  also  deprive  the  blood  of  the 
carotid  of  a portion  of  the  momentum  which  it  has  retain- 
ed after  leaving  the  bone. 

The  object  of  these  various  flexures  of  the  internal  caro- 
tid appears  to  be  analogous  to  that  of  the  Rete  Mirabile 
in  certain  quadrupeds,  which  is  formed  by  the  division  of 


254 


Ophthalmic  Artery: 

this  artery  into  many  small  branches,  that  reunite  again, 
without  producing  any  other  effect  than  the  diminution  of 
the  momentum  of  the  blood. 

During  its  course  from  the  place  of  bifurcation  to  i^s 
entrance  into  the  carotid  canal,  the  internal  carotid  artery 
very  rarely  sends  off  any  branches.  In  the  canal  it  gives 
off  a small  twig  which  enters  the  cavity  of  the  tympanum; 
and  sometimes  a second  which  unites  with  the  Pterygoid 
branch  of  the  internal  maxillary. 

As  it  goes  by  the  sella  tnrcica,  it  passes  through  the 
cavernous  sinuses,  and  gives  off  two  branches  which  are 
called  the  Posterior  and  Anterior  arteries  of  the  Caver- 
nous Sinus  or  Receptacle. 

The  posterior  branch  goes  to  that  part  of  the  dura  mater 
which  is  connected  with  the  posterior  clinoid  process,  and 
the  cuneiform  process  of  the  occipital  bone.  It  likewise 
gives  branches  to  several  of  the  nerves  which  are  con- 
tiguous, and  to  the  pituitary  gland. 

The  anterior  artery  also  gives  branches  to  the  contigu- 
ous nerves,  to  the  dura  mater,  and  the  pituitary  gland. 

When  the  internal  carotid  turns  upwards  at  the  anterior 
clinoid  process,  it  sends  off  the 

OPHTHALMIC  ARTERY, 

Which  passes  under  the  optic  nerve  through  the  foramen 
opticum  into  the  orbit  of  the  eye,  and  is  about  two  lines 
in  diameter. 

Although  this  artery  enters  the  orbit  under  the  optic 
nerve,  it  soon  takes  a position  on  the  outside  of  it;  but 
afterwards  gradually  proceeds  to  the  inner  side  of  the 
orbit,  crossing  over  this  nerve  in  an  oblique  direction,  and 
finally  passes  out  of  the  orbit  near  the  internal  angle.  In 
this  spiral  course  it  sends  off  numerous  branches,  viz. 


255 


Distribution  of  its  Branches. 

A.  To  those  parts  which  are  auxiliary  to  the  eye. 

b.  To  the  ball  of  the  eye. 

c.  To  the  cavity  of  the  nose,  through  small  foramina 
in  the  ethmoid  bone,  and 

D.  To  the  forehead  and  external  side  of  the  nose. 

These  branches  generally  go  off  in  the  following  order. 

The  Lachrymal  artery  arises  soon  after  the  ophthalmic 
arrives  within  the  orbit,  and  passes  above  the  abductor 
muscle  to  the  lachrymal  gland,  where  it  terminates,  send- 
ing off  many  small  branches  in  its  course. 

The  Central  artery  of  the  retina  also  leaves  the  ophthal- 
mic soon  after  its  arrival  in  the  orbit:  it  is  a small  vessel 
which  penetrates  into  the  center  of  the  optic  nerve,  and 
passing  with  it  into  the  eye  is  spread  upon  the  internal  sur- 
face of  the  retina.  Here  it  appears  to  terminate  in  the 
adult;  but  in  the  foetus  it  is  continued  through  the  vitreous 
humour  to  the  capsule  of  the  crystalline  lens. 

While  the  ophthalmic  is  passing  over  the  optic  nerve 
the  branches  which  enter  the  ball  of  the  eye  leave  it. 
Their  number  varies,  but  they  form  three  classes,  viz. 
The  Long  Ciliary , the  Short  Ciliary , and  the  Anterior 
Ciliary  Arteries.  (See  description  of  the  eye,  vol.  i.  p.  353.) 
The  supra  orbitary  and  muscular  branches  leave  it  also 
near  the  same  places. 

The  Supra  Orbitary  Branch  often  gives  off  several 
muscular  twigs:  but  it  passes  out  of  the  orbit  through  the 
supra  orbitar  foramen,  and  generally  divides  into  two 
branches,  one  of  which  is  spent  upon  the  periosteum,  and 
the  other  upon  the  skin  and  muscles  of  the  forehead. 

There  are  sometimes  two  muscular  branches,  a Superior 
and  an  Lnferior.  The  superior  branch  is  often  deficient: 
when  it  exists  it  supplies  the  levator  palpebrae,  the  levator 
oculi,  obliquus  superior,  &c.;  but  these  parts  are  often 


256  Branches  of  the  Ophthalmic  Artery. 

supplied  by  the  branches  above  mentioned.  The  supra 
orbitar  so  frequently  gives  off  branches  to  the  muscles  that 
it  has  been  called  the  Superior  Muscular  Branch.  The 
inferior  muscular  branch  is  more  constant.  It  commonly 
supplies  the  rectus  inferior,  the  adductor,  and  the  inferior 
oblique  muscles,  and  also  the  lachrymal  sac,  and  the  lower 
eyelid,  &c. 

When  the  artery  is  on  the  inside  of  the  nerve  it  sends 
off  the  two  branches  to  the  cavity  of  the  nose,  viz.  The 
Ethmoidal  Arteries ; and  also,  branches  to  the  eyelids. 

The  Posterior  Ethmoidal  branch  is  first.  It  passes  be- 
tween the  levator  and  adductor  muscles,  and  above  the 
obliquus  superior;  and  penetrates  the  cavity  of  the  crani- 
um by  the  posterior  orbitary  foramen:  after  giving  some 
twigs  to  the  dura  mater,  it  passes  to  the  posterior  cells 
of  the  ethmoid  by  the  foramina  of  the  cribriform  plate 
of  that  bone,  and  sends  a small  branch  to  the  Schneiderian 
membrane  on  the  back  part  of  the  septum  of  the  nose. 

The  Anterior  Ethmoidal  artery  arises  from  the  ophthal- 
mic nearly  opposite  to  the  anterior  orbitary  foramen, 
through  which  it  passes:  and  after  entering  the  cranium 
is  distributed  like  the  other  through  some  of  the  foramina 
of  the  cribriform  plate  to  the  anterior  cells  of  the  ethmoid 
bone,  and  to  the  anterior  part  of  the  Schneiderian  mem- 
brane on  the  septum  of  the  nose,  to  which  it  sends  a 
considerable  branch. 

In  its  course  it  sends  twigs  to  the  frontal  sinuses,  and  to 
the  dura  mater  and  its  falciform  process. 

The  arteries  of  the  Palpebrce  are  called  Superior  and  In- 
ferior; they  leave  the  ophthalmic  near  the  loop  or  pully  of 
the  superior  oblique  muscle.  The  inferior  comes  off  first; 
it  sends  branches  to  the  ligaments  of  the  tarsus,  the  carun- 
cula  lachrymalis,  and  the  parts  connected  with  the  cartilage 


Internal  Carotid.  Middle  Artery  of  the  Brain.  257 

of  the  under  eyelid,  and  unites  with  the  lachrymal  artery 
near  the  external  canthus,  forming  an  arch  c&led  the  Infe- 
rior Tarsal  Arch. 

The  Superior  Artery  supplies  the  superior  part  of  the 
orbicularis  muscle,  the  ligament  and  caruncula  also:  and 
it  likewise  unites  with  a twig  of  the  lachrymal,  and  forms 
the  superior  tarsal  arch. 

Soon  after  sending  off  the  palpebral  branches,  the 
Ophthalmic  Artery  arrives  at  the  internal  canthus,  and  then 
finally  divides  into  two  branches,  the  nasal  and  the.  frontal. 

The  Nasal  Branch  passes  above  the  superior  part  of  the 
lachrymal  sac  and  the  ligament  of  the  eyelid  to  the  nose; 
after  sending  a twig  to  the  frontal  muscle  and  the  lachry- 
mal sac,  it  passes  down  the  side  of  the  nose  and  anastomo- 
ses with  the  facial  artery. 

The  Frontal  Artery  is  not  so  large  as  the  nasal;  it  gene- 
rally divides  into  three  parts.  A superciliary  branch  which 
is  principally  spent  upon  the  eyebrows;  a superficial  branch 
which  is  spent  upon  the  forehead;  and  a branch  which  is 
distributed  to  the  pericranium. 

The  INTERNAL  CAROTID , soon  after  parting  with 
the  ophthalmic,  sends  off,  in  a posterior  direction,  a branch 
to  join  one  from  the  vertebral  artery.  From  its  destination 
this  vessel  is  called  the  arteria  communicans. 

After  this  it  sends  off  another  branch,  which  is  so  large 
that  it  may  be  considered  as  a continuation  of  the  main 
trunk:  this  is  called  the  middle  artery  of  The  brain, 
or  the  arteria  sylviana.  It  runs  outwards  nearly  in  the 
direction  of  the  fossa  Sylvii,  which  separates  the  anterior 
from  the  middle  lobes  of  the  cerebrum.  In  its  course  it 
divides  and  subdivides  into  numerous  branches  which  are 
spread  upon  the  Pia  Mater , and  finally  enter  the  surface 
of  the  brain  in  a very  minute  state. 

Vol.  II.  2 K 


258  Position  of  the  Right  and 

The  internal  carotid  then  terminates  in  a branch  which 
is  smaller  than  the  last  mentioned,  and  from  its  situation  is 
called  the  anterior  artery  of  the  brain,  or  arteria 
callosa.  This  vessel  first  inclines  towards  its  fellow  on 
the  opposite  side,  and  after  approaching  within  half  an 
inch  of  it,  forms  another  curve,  and  runs  forward  to  the 
anterior  part  of  the  brain,  dividing  itself  gradually  inta 
branches  which  pass  in  several  directions. 

When  these  anterior  arteries  are  nearest  to  each  other, 
a small  Transverse  branch,  which  passes  at  right  angles, 
connects  them  together.  This  branch  completes  the  ante- 
rior part  of  the  Circle  of  Willis.  It  crosses  immediately 
before  the  sella  turcica  and  pituitary  gland,  and  sends  off 
branches  which,  pass  to  the  third  ventricle,  to  the  fornix 
and  septum  lucidum,  and  also  to  the  pia  mater. 

The  anterior  arteries  of  the  brain  also  send  off 
branches  to  the  optic  and  olfactory  nerves;  to  the  opposite 
surfaces  of  the  two  hemispheres  on  each  side  of  the  falx; 
to  their  inferior  surfaces,  and  to  the  corpus  callosum. 

They  have  likewise  some  branches  which  anastomose 
with  those  of  the  middle  artery  of  the  brain,  and  of  the 
vertebral  artery. 

The  SUBCLAVIAN  Arteries. 

The  RIGHT  SUBCLAVIAN  may  be  considered  as 
the  continuation  of  the  arteria  innominata.  This  last 
mentioned  artery,  after  leaving  the  aorta,  forms  a curve 
or  arch,  which  extends  obliquely  backwards  and  out- 
wards, over  the  first  rib  to  the  axilla,  crossing  the  trachea 
in  its  course.  At  the  distance  of  an  inch  and  a quarter,  or 
an  inch  and  a half  from  its  origin,  it  sends  off  the  right 
carotid,  and  then,  assuming  the  name  of  Right  Subclavian , 
continues  in  the  above  stated  direction. 


Left  Subclavian  arteries.  259 

The  cord  of  the  curve  of  this  artery,  and  the  cord  of 
the  curve  of  the  aorta,  are  not  in  the  same  direction,  but 
form  an  angle  with  each  other. 

The  position  of  the  LEFT  SUBCLAVlAN'is  somewhat 
different  from  that  of  the  right.  Its  origin  is  posterior,  and, 
therefore,  the  direction  of  the  cord  of  its  curve  is  more 
immediately  lateral.  The  curve  or  arch  is  also  smaller.  The 
situation  of  the  two  subclavians  as  relative  to  the  con- 
tiguous parts,  is,  therefore,  somewhat  different;  but  each 
of  them  proceeds  between  the  anterior  and  the  middle 
scaleni  muscles,  and  when  they  have  arrived  at  these 
muscles,  their  respective  positions  are  very  similar. 

The  anterior  and  middle  scaleni  muscles  arise  from  the 
transverse  processes  of  several  of  the  cervical  vertebra,  and 
are  inserted  into  the  first  rib,  one  before  the  other,  so  as 
to  leave  a considerable  space  between  them. The  subclavian 
arteries  pass  through  this  space,  and  before  they  arrive  at 
it,  but  when  they  are  very  near  the  above  mentioned 
muscles,  they  send  off  several  very  important  branches  in 
various  directions,  viz.  to  the  cavity  of  the  cranium,  to  the 
parietes  of  the  thorax,  to  the  thyroid  gland,  and  to  the 
lower  part  of  the  neck. 

They  proceed  near  to  the  scaleni  muscles  before  they 
send  off  any  branches;  and  it  is  to  be  observed,  that  the 
subclavian  veins  which  correspond  with  these  arteries, 
are  anterior  to  them,  for  they  pass  before  the  scaleni 
muscles,  and  not  between  them. 

The  internal  mammary  Artery  . 

Goes  downwards,  from  the  lower  and  anterior  part  of  the 
subclavian,  along  the  inner  side  of  the  anterior  scalenus 
muscle.  It  proceeds,  exterior  to  the  pleura,  across  the  car- 
tilages of  the  true  ribs,  and  near  their  middle;  and,  con- 


260  Course  and  Distribution  of  the  Inferior 

tinuing  between  the  cartilages  and  the  diaphragm,  exterior 
to  the  peritoneum,  terminates  on  the  rectus  abdominis 
muscle,  in  branches  which  anastomose  with  those  of  the 
epigastric  artery.  In  .this  course  it  gives  branches  to  almost 
all  the  parts  to  which  it  is  contiguous,  viz.  to  the  muscles 
and  glands  at  the  lower  part  of  the  neck;  to  the  thymus 
gland;  to  the  parts  in  the  intercostal  spaces;  to  the  sternum; 
to  the  mediastinum  and  pericardium;  to  the  diaphragm 
and  to  the  muscles  of  the  abdomen. 

From  some  of  its  ramifications  upon  the  parts  between 
the  ribs,  small  branches  go  off  to  the  mamma,  and  thereby 
give  a name  to  the  artery.  There  is  also  a small  vessel 
which  is  sent  off  by  the  mammary  artery,  or  by  one  of  its 
upper  branches,  which  accompanies  the  phrenic  nerve  to 
the  diaphragm. 

The  inferior  thyroid  Artery 
Arises  from  the  upper  side  of  the  subclavian  nearly  op- 
posite to  the  origin  of  the  internal  mammary.  It  passes 
upwards  and  inwards,  between  the  carotid  artery  and  the 
spine,  to  the  thyroid  gland:  then  it  anastomoses  with  the 
branches  of  the  superior  thyroid  on  the  same  side,  and 
with  those  of  its  fellow  on  the  opposite  side. 

This  vessel  sometimes  sends  off  large  branches  to  the 
muscles  at  the  lower  part  of  the  neck. 

The  vertebral  Artery 

Arises  from  the  upper  and  posterior  part  of  the  subclavian. 
It  goes  upwards  and  backwards  between  the  muscles  which 
lie  on  the  front  of  the  spine,  and  passing  under  the  trans- 
verse process  of  the  sixth  or  seventh  cervical  vertebra, 
enters  into  the  canal  formed  in  the  transverse  processes 
of  the  vertebrae.  In  this  course,  as  it  proceeds  from  the 


Thyroid,  and  the  Vertebral  Arteries,.  261 

third  to  the  second  cervical  vertebra,  it  inclines  outwards 
laterally,  and,  in  its  passage  from  the  transverse  process  of 
the  second  to  that  of  the  first  vertebra,  it  forms  a consi- 
derable curve,  the  convexity  of  which  has  a lateral  and 
external  aspect.  After  passing  the  transverse  processes  of 
the  Atlas , it  is  turned  suddenly  backwards,  in  a groove, 
and  finally  passes  through  the  great  occipital  foramen  into 
the  cavity  of  the  cranium.  It  then  proceeds  upon  the 
cuneiform  process  of  the  occipital  bone,  under  the  Medulla 
Oblongata , and  joins  its  fellow  so  as  to  form  an  acute  angle 
with  it  near  the  union  of  the  medulla  oblongata  with  the 
pons  Varolii.  From  each  of  the  vertebral  arteries,  before 
their  union,  there  generally  goes  off  a small  branch  called 
the  Posterior  Meningeal , which  is  spent  upon  the  posterior 
part  of  the  dura  mater. 

The  trunk  formed  by  the  union  of  the  vertebral  arteries 
is  called 

The  BASILAR  Artery. 

It  extends  forward  near  to  the  anterior  part  of  the  pons 
Varolii,  where  it  bifurcates;  but  previously  sends  off  se- 
veral branches  on  each  side.  The  first  pair  go  off  in  a 
lateral  direction,  soon  after  its  commencement,  near  the 
back  part  of  the  pons  Varolii,  and  are  spent  upon  the  me- 
dulla oblongata,  the  pons  Varolii,  and  the  other  contiguous 
parts,  and  also  upon  the  fourth  ventricle  and  the  Plexus 
Choroides  of  that  cavity.  They  are  called  the  Posterior  or 
Inferior  Arteries  of  the  Cerebellum. 

Two  other  lateral  branches,  which  are  called  the  Su- 
perior Arteries  of  the  Cerebellum,  go  off  from  the  basilar 
artery,  near  its  anterior  extremity.  These  are  principally 
spent  upon  the  crura  of  the  cerebellum  and  cerebrum; 
upon  the  cerebellum  itself,  and  the  contiguous  parts. 


262  Superior  Intercostal  Artery. 

Soon  after  sending  off  the  last  mentioned  arteries,  the 
basilar  artery  divides  into  two  branches,  which  also 
take  a lateral  direction,  and  are  of  considerable  size.  In 
their  course  outward,  these  branches  are  curved  with 
their  convexity  forward.  About  ten  or  twelve  lines  from 
its  commencement,  each  of  them  sends  off  a branch  call- 
ed the  arteria  communic  ans,  which  passes  directly  for- 
ward, and  communicates  with  the  internal  carotid,  thus 
forming  the  arrangement,  which  is  called  the  Circle  of 
Willis.*  After  sending  off  these  arteries,  they  continue 
their  lateral  direction,  and  are  distributed  principally  to 
the  posterior  parts  of  the  cerebrum.  These  terminating 
branches  of  the  basilar  artery  are  called  the  Posterior 
Arteries  of  the  Cerebrum. 

The  superior  intercostal  Artery 
Arises  from  the  upper  part  of  the  Subclavian , after  the 
Vertebral  and  Thyroid  arteries,  and  very  near  them.  It  de- 
scends by  the  side  of  the  spine  across  the  first  and  second 
ribs,  hear  their  heads,  and  exterior  to  the  great  intercostal 
nerve.  It  generally  forms  two  branches,  which  are  ap- 
propriated to  the  muscles,  &c.,  in  the  first  and  second 
intercostal  spaces,  and  sometimes  a small  branch  is  con- 
tinued to  the  third  intercostal  space.  From  each  of  these 
branches  a small  vessel  proceeds  backwards,  and  is  spent 

* The  arteria  communicans  is  also  considered  as  a branch  of  the 
Internal  Carotid.  The  arrangement  here  alluded  to  is  very  remarkable. 
As  the  branches  which  pass  off  laterally  from  the  single  trunk  of  the 
Basilar  Artery  unite  to  the  Internal  Carotids,  and  the  Internal  Carotids 
are  united  to  each  other,  there  is  an  uninterrupted  continuation  of 
artery,  which  incloses  a portion  of  space  of  a determined  form;  but 
this  form  resembles  an  oblong  square  more  than  a circle.  By  this  con- 
nexion blood  will  pass  from  any  one  of  the  four  arteries  of  the  brain 
fo  all  the  others. 


Arteries  of  the  lower  part  of  the  Neck.  263 

upon  the  contiguous  muscles,  &c.,  on  the  back  of  the 
thorax.  The  intercostal  artery  also  sends  a branch 
upwards  to  the  deep  seated  parts  of  the  neck. 

In  addition  to  the  arteries  above  mentioned,  there  are 
several  others  of  considerable  size,  which  originate  either 
directly  or  indirectly  from  the  SUBCLAVIAN , and  are 
spent  upon  the  lower  portion  of  the  neck,  and  the  conti- 
guous parts.  These  arteries  are  very  different  in  different 
subjects,  especially  as  to  their  origin.  Two  of  them,  which 
have  been  called  the  anterior  and  posterior  cervi- 
cals,  are  generally  distributed  to  the  muscles  and  other 
parts  which  lie  on  the  lower  portion  of  the  neck  anteriorly 
and  posteriorly. 

A third,  which  passes  transversely  on  the  lower  part  of 
the  neck,  is  called  the  superior  scapular. 

In  some  cases  the  two  cervical  arteries  arise  from 
the  subclavian,  after  the  mammary  and  the  thyroid,  in  a 
common  trunk,  which  soon  divides.  Very  frequently 
they  go  off  from  the  Inferior  Thyroid.  Sometimes  one  of 
them  goes  off  from  the  Inferior  Thyroid , and  the  other 
from  one  of  the  branches  of  the  Subclavian.* 

The  Superior  Scapular  most  cemmonly  arises  with 
some  other  artery,  and  very  often  from  the  Inferior 
Thyroid.  It  runs  transversely  outwards,  within  and  above 

* Haller  paid  great  attention  to  the  arterial  system,  and  made  many 
dissections,  with  a view  to  engravings  of  it,  which  he  published  with 
descriptions,  in  folio  fasciculi. 

These  fasciculi  have  been  collected,  and,  with  some  other  engrav- 
ings, form  a large  volume,  entitled  ICONES  ANATOMICAL,  which 
is  truly  valuable. 

There  are  some  very  interesting  observations  on  this  work  of  Hal- 
ler’s, and  also  on  these  arteries,  in  a DESCRIPTION  OF  THE 
ARTERIES,  by  Dr.  Barclay  of  Edinburgh,  which  I have  read  with 
advantage,  as  well  as  a work  on  the  muscles  by  the  same  author. 


264  Branches  that  go  off  in  the  Axilla * 

the  clavicle,  and  passing  through  the  notch  in  the  upper 
costa  of  the  scapula,  divides  into  branches  which  are  dis- 
tributed to  the  parts  on  the  dorsum  of  that  bone. 

The  SUBCLAVIAN  ARTERY,  in  its  progress  from 
the  aorta  to  the  axilla,  forms  an  arch  or  curve,  over  the 
first  rib,  as  has  been  already  observed.  The  anterior 
scalenus  muscle  is  before  it,  and  the  great  nerves  of  the 
upper  extremity  are  above  it.  After  passing  between  the 
scaleni  it  descends  upon  the  first  and  second  rib  into  the 
axilla.  The  nerves  which  were  above,  descend  with  it: 
at  first  they  are  necessarily  exterior  to  it,  but  they  form  a 
plexus  which  the  artery  enters  into,  so  as  to  be  partly 
surrounded  by  them.  This  course  of  the  artery  is  ob- 
liquely under  the  clavicle,  and  behind  the  pectoral  muscle. 
In  the  axilla,  the  vessel  and  nerves  which  surround  it  are 
placed  between  the  tendons  of  the  pectoralis  and  the 
latissimus  dorsi  muscles.  Here  the  artery  takes  the  name 
oi  AXILLARY j and  sends  off  several  important  branches. 

The  principal  branches  that  go  off  from  the  axillary 
artery  are  distributed 

1st.  Anteriorly,  to  the  pectoral  muscle,  and  the  parts  on 
the  anterior  surface  of  the  thorax. 

2d.  Posteriorly,  to  the  muscles  which  are  on  the  scapula 
and  contiguous  to  it;  and 

3d.  To  the  parts  which  are  near  the  upper  extremity  of 
the  os  humeri. 

Anterior  Branches. 

The  arteries  which  go  to  the  pectoral  muscle,  &c.,  are 
very  various  in  different  subjects,  both  as  to  their  number, 
origin,  and  size. 

They  have  also  been  called  by  different  names,  as 
•THORACICjE,  MAMMARIjE  externa,  See. 


265 


Branches  that  go  off  in  the  Axilla. 

There  are  almost  always  three  of  them,  and  very  often 
more;  one  of  them,  which  is  called  by  several  authors  the 
Acromialis , proceeds  towards  the  end  of  the  clavicle,  and 
generally  passes  out  at  the  interval  between  the  deltoid 
and  the  pectoral  muscle,  sending  various  branches  to  the 
contiguous  parts;  the  largest  of  its  branches  often  passing 
in  the  direction  of  the  interstice  between  those  muscles. 

Another  of  these  arteries,  which  is  called  Superior 
1 Thoracic , is  generally  very  small:  it  often  is  a branch 
of  the  above  mentioned  Acromialis. 

There  is  very  often  to  be  found  here  an  artery  called  the 
Inferior  Thoracic , or  the  External  Mammary , which  is  of 
considerable  length,  although  its  diameter  is  not  very 
great.  This  artery  originates  near  the  two  last  mentioned, 
and  sometimes  from  the  Acromialis.  It  often  extends 
downwards  as  low  as  th#  sixth  rib,  and  sends  branches  to 
the  anterior  part  of  the  thorax,  to  the  mamma,  and  the 
other  contiguous  parts.  Many  of  the  small  branches  of  this^ 
artery  anastomose  very  freely  with  those  of  the  internal 
mammary. 

There  are  always  small  arterial  branches  in  the  axilla, 
which  ramify  upon  the  glands  and  adipose  matter  always 
existing  there.  They  often  arise  by  one  common  trunk, 
which  is  called  the  Axillary  Thoracic. 

Posterior  Branch. 

One  large  artery  is  commonly  sent  to  the  muscles  on 
the  scapula,  which  is  called  the  scapular,  the  common 
scapular,  or  the  internal  scapular.  It  commonly 
passes  off  from  the  axillary  after  the  thoracic  arteries, 
and  supplies  the  muscles  on  both  surfaces  of  the  scapula. 
This  large  vessel  passes  downwards  a short  distance  in 
the  direction  of  the  inferior  costa  of  the  scapula,  and  «oon 
sends  off  a branch  that  winds  round  to  the  dorsum  of 
Vol.  II.  2 L 


266  Branches  that  go  off  in  the  Axilla . 

the  bone,  to  be  distributed  to  the  infra  spinatus  and 
the  contiguous  muscles,  which  is  called  the  Dorsalis 
Scapula \ The  main  trunk  then  inclines  to  the  subscapularis 
muscle,  and  generally  divides  into  two  branches,  which 
are  distributed  to  the  subscapularis,  teres  major,  latissimus 
dorsi,  &c. 

Sometimes  the  scapular  artery  divides  into  two 
branches  before  it  sends  off  the  dorsal.  In  this  case  the 
last  mentioned  artery  goes  pff  from  one  of  those  branches. 

Branches  near  the  Os  Humeri. 

The  arteries  which  are  near  the  body  of  the  os  humeri 
at  its  upper  end,  are  generally  two  in  number,  and  deno- 
minated the  Anterior  and  Posterior  Circumflexes.  Some- 
times they  arise  separately,  and  sometimes  in  a common 
trunk  from  the  AXILLARY  artery.  Frequently  one  of 
them  arises  from  the  scapular. 

The  Anterior  Circumflex  passes  between  the  united 
heads  of  the  biceps  and  coraco  brachialis  muscles  and 
the  body  of  the  os  humeri,  at  a small  distance  below  its 
head.  It  sends  branches  to  the  capsular  ligament,  the  pe- 
riosteum of  the  os  humeri,  the  membranes  of  the  groove 
for  the  long  head  of  the  biceps,  the  upper  portions  of 
the  biceps  and  coraco  brachialis,  and  some  contiguous 
muscles. 

The  Posterior  Circumflex  proceeds  between  the  sub- 
scapularis and  teres  major  muscles,  and  continues  be- 
tween the  os  humeri  and  the  head  of  the  triceps  and  the 
deltoides.  It  is  distribute  d to  the  muscles  and  parts  about 
the  joint,  especially  the  deltoides. 

These  arteries  surround  the  os  humeri,  and  the  small 
branches  anastomose  with  each  other.  The  Posterior  Cir- 
cumflex is  much  larger  than  the  Anterior. 


267 


Situation  of  the  Humeral  Artery. 

The  great  artery  of  the  arm  proceeds  from  the  axilla  to 
the  elbow ; and,  during  this  course,  is  generally  denominated 

The  HUMERAL  Artery.* 

Its  direction  is  influenced  by  the  position  of  the  os  humeri. 
When  the  arm  hangs  down,  with  the  palm  of  the  hand 
presenting  forward,  this  direction  is  somewhat  spiral.  The 
situation  of  the  artery  is  on  the  inside  of  the  biceps 
muscle,  and  between  that  muscle  and  the  triceps  extensor. 
It  also  continues  very  near  and  on  the  inside  of  the  tendon 
of  the  biceps,  and  under  the  Aponeurosis  which  proceeds 
from  that  tendon.  In  consequence  of  the  spiral  or  oblique 
course  of  the  artery,  its  direction  would  be  from  the 
inside  of  the  tendon  of  the  biceps  to  the  radial  side  of  the 
fore  arm,  but  soon  after  it  passes  across  the  joint  of  the  el- 
bow, it  divides  into  two  branches:  one  which  preserves,  for 
some  distance,  the  direction  of  the  Main  Trunk , is  called 
the  radial  artery:  the  other,  which  inclines  obliquely 
downwards  and  towards  the  ulna,  is  the  common  trunk 
of  the  ulnar  and  interosseal  arteries. 

During  this  course,  the  HUMERAL  artery  sends  off 
several  branches  to  the  muscles  and  other  parts  on  the 
os  humeri.  The  largest  of  them  is  denominated  the  Pro- 
funda Humeri , or  Spiralis.  This  artery  very  often  arises 
as  high  as  the  insertion  of  the  latissimus  dorsi,  and  passing 
between  the  heads  of  the  triceps  extensor  muscle,  proceeds 
downwards  under  that  muscle,  in  a spiral  direction,  to- 
wards the  external  or  radial  condyle.  It  sends  several 
branches  to  the  triceps  and  the  contiguous  muscles,  and 
one  considerable  branch,  which  is  generally  called  the 
Profunda  Minor , to  the  parts  contiguous  to  the  internal 


* It  is  also  called  Brachial  Artery  by  several  writers. 


268  Branches  of  the  Humeral  Artery. 

condyle.  The  ramifications  of  these  branches  near  the 
condyle  frequently  anastomose  with  small  branches  of  the 
radial  and  ulnar  arteries.* 

A small  branch  frequently  arises  from  the  humeral 
artery,  at  a short  distance  from  the  Profunda  Humeri , 
which  sends  a ramification  to  the  medullary  foramen  of 
the  os  humeri.  This  vessel  is,  therefore,  denominated 

Arteria  Nutritia. 

There  are  verv  often  several  anastomoses  between  the 
branches  of  the  HUMERAL  artery,  which  originate 
above  the  elbow,  and  certain  branches  of  the  radial 
and  ulnar  arteries,  which  are  called  from  their  direc- 
tion recurrents.  Among  these  arteries  there  is  generally 
one  of  considerable  size,  which  proceeds  across  the  elbow 
joint  near  the  internal  condyle.  Sometimes  this  is  the 
ulnar  recurrent,  which  goes  up  to  anastomose  with  the 
branches  of  the  profunda;  but  more  frequently  it  is  a 
separate  branch  of  the  HUMERAL  artery,  which  goes 
off  a little  above  the  elbow,  and  passes  across  the  articu- 
lation, near  the  internal  condyle,  to  anastomose  with  the 
branches  of  the  ulnar  artery.  This  artery  is  denominated 
the  Anastomotica. 

There  are  often  other  branches  sent  off  by  the  HU- 
MERAL artery;  but  they  are  commonly  small,  and  very 
irregular. 

The  two  great  ramifications  of  the  HUMERAL  artery 
on  the  fore  arm  have  very  different  directions.  The 
radial  artery  preserving  the  course  of  the  main  trunk, 
while  the  common  trunk  of  the  ulnar  and  interosseal 

* The  Profunda  sometimes  originates  from  the  scapular,  or  one  of 
the  circumflex.  The  profunda  minor  sometimes  has  a distinct  and 
separate  origin,  lower  down  than  the  other. 


Course  and  Ramifications  of  the  Radial  Artery.  269 

projects  from  it  in  a direction  downwards  and  towards 
the  ulna,  passing  under  the  pronator  teres,  &c. 

The  radial  Artery , 

Passing  over  the  pronator  teres  muscle,  proceeds  between 
the  supinator  radii  longus  and  the  flexor  carpi  radialis, 
very  near  to  the  lower  end  of  the  radius,  without  changing 
its  direction  materially,  being  deep  seated  above  and  su- 
perficial below;  it  then  alters  its  course,  and,  passing  under 
the  tendons  of  the  extensors  of  the  thumb,  to  the  back 
part  of  the  radius,  it  continues  between  the  metacarpal 
bones  of  the  thumb  and  of  the  index  finger,  when  it  divides 
into  three  branches. 

In  this  course  it  gives  off  but  few  branches.  The  first 
is  the  Radial  Recurrent , which  passes  upwards  and  to- 
wards the  external  condyle,  and  frequently  anastomoses 
with  the  ramifications  of  the  profunda  humeri. 

The  branches  which  it  sends  off  between  the  origin  of 
the  recurrent  and  the  lower  end  of  the  radius  are  gene- 
rally very  small,  and  distributed  to  the  parts  immediately 
contiguous  to  the  artery.  Before  it  turns  under  the  ten- 
dons of  the  extensors  of  the  thumb,  it  sends  a branch 
over  the  wrist  towards  the  root  of  the  thumb,  from  which 
proceeds  a branch  to  anastomose  with  the  volar  branch  of 
the  ulnar;  and  another,  not  so  large,  which  is  frequently 
continued  on  the  radial  or  external  side  of  the  thumb, 
very  near  to  its  extremity.  While  the  radial  artery  is 
under  the  aforesaid  tendons,  it  sends  off"  small  branches 
to  the  back  of  the  wrist  and  back  of  the  hand,  and  often 
to  the  back  of  the  thumb.  Those  which  are  distributed  to 
the  wrist  and  back  of  the  hand,  generally  anastomose  with 
the  small  branches  of  the  ulnar  and  interosseal  arteries. 

The  three  branches  into  which  the  radial  artery 


270  Origin  of  the  Ulnar  and  Interosseal  Arteries. 

divides  between  the  metacarpal  bones  of  the  thumb  and 
index  are,  1st.  a branch  to  the  external  side  of  the  index; 
2dly,  a branch  to  the  thumb , that  sometimes  divides  into  two 
which  pass  up  on  the  anterior  or  volar  surface,  and  some- 
times continues,  without  much  diminution,  on  the  internal 
side  of  the  thumb,  near  to  the  end  of  the  last  phalanx; 
and,  3dly,  a branch,  called  Palmaris  Profunda , which 
dips  down  into  the  palm  of  the  hand,  and,  proceeding 
in  contact  with  the  metacarpal  bones,  under  the  flexor 
tendons,  &c.,  forms  an  arch  which  extends  across  the 
hand,  and  often  terminates  by  anastomosis  with  another 
arch,  soon  to  be  described,  which  is  formed  by  the  ulnar 
artery. 

This  flexure,  which  is  denominated  Arcus  Profundus , 
sends  off  branches  of  a very  small  size,  which  are  distri- 
buted to  the  bones,  ligaments,  muscles,  &c.,  contiguous 
to  it. 

The  common  trunk  of  the  ulnar  and  INTEROSSEAL 
Arteries 

Passes  under  several  of  the  muscles  which  originate  from 
the  internal  condyle,  and  between  the  flexor  sublimis  and 
the  flexor  profundus.  Before  the  Ulnar  Recurrent  goes  off 
from  this  vessel,  the  interosseal  artery  often  leaves 
it.  This  recurrent  artery  passes  upwards  between  the 
muscles  of  the  internal  condyle,  and  distributes  branches 
among  them.  It  then  passes  up  in  the  groove  behind  the 
internal  condyle,  and  anastomoses  with  the  branches  of 
the  Anastomotica  or  Profunda  Humeri. 

The  ulnar  and  interosseal  arteries  separate  from  each 
other  at  the  distance  of  fifteen  or  twenty  lines  from  the 
origin  of  the  radial  artery,  very  near  the  commencement 
of  the  interosseal  ligament. 


Interosseal  and  Ulnar  Arteries . 


271 


The  interosseal  Artery , 

In  a majority  of  cases  arises  in  a single  branch  from  the 
common  trunk  of  the  ulnar  and  interosseal.  When  it  does 
so,  the  single  branch  soon  sends  off  the  Posterior  Inte- 
rosseal artery,  which  perforates  the  interosseous  ligament, 
and  passes  down  on  its  posterior  surface,  while  the  main 
branch  continues  on  the  anterior  surface  of  the  ligament,, 
and  is  denominated  the  Anterior  Interosseal  Artery.  In 
some  cases  the  main  branch  proceeds  on  the  anterior 
surface  as  low  as  the  upper  edge  of  the  pronator  qua- 
dratus  muscle,  before  it  sends  off  the  posterior  branch. 
Sometimes  the  anterior  and  posterior  interosseals  arise 
separately.  In  this  case  the  posterior  soon  perforates  the 
ligament. 

The  Anterior  Interosseal  passes  down  almost  in  contact 
with  the  ligament,  and  gives  branches  to  the  contiguous 
parts  in  its  course.  It  generally  perforates  the  interosseous 
ligament  near  the  wrist,  and  sends  off  many  small  branches 
to  the  back  of  the  wrist  and  hand,  which  anastomose  with 
the  small  branches  of  the  radial  and  the  posterior  interos- 
seal arteries. 

The  Posterior  Interosseal  soon  gives  off  a recurrent  or 
anastomosing  branch,  and  then  proceeds  downwards  to- 
wards the  wrist,  sending  branches  in  its  course  to  the 
extensor  muscles  and  tendons. 

This  vessel  sometimes  divides  into  two  branches. 

The  ulnar  Artery. 

The  ulnar  artery  proceeds  among  the  muscles  obliquely 
downwards,  and  is  not  superficial  until  it  has  arrived  within 
three  or  four  inches  of  the  carpus:  it  then  continues  towards 
the  hand,  seitding  off  very  small  branches  in  its  progress. 


272  Course  of  the  Ulnar  Artery , and 

It  passes  over  the  annular  ligament  at  the  wrist,  and  winds 
round  the  pisiform  bone:  here  it  is  supported  by  a delicate 
ligament,  which  seems  to  lie  upon  it:  from  this  it  passes 
upon  the  palm  of  the  hand,  under  the  aponeurosis  palma- 
ris,  and  over  the  tendons  of  the  flexors  of  the  fingers. 
When  thus  situated,  it  forms,  in  perhaps  a majority  of 
subjects,  an  arch  or  bow,  called  arcus  sublimis,  which 
extends  across  the  palm  of  the  hand,  from  the  ulnar  to- 
wards the  radial  edge,  and,  after  sending  branches  to  the 
fingers,  &c.,  from  its  convex  side,  terminates  near  the  root 
of  the  thumb,  by  anastomosis  with  that  important  branch 
of  the  radial  artery,  which  passes  up  on  the  inside  of  the 
thumb.  The  arcus  sublimis  almost  always  sends  off- 
small  branches  to  the  integuments,  &c.,  on  the  palm  of 
the  hand.  It  often  sends  off,  near  the  root  of  the  me- 
tacarpal bone  of  the  little  finger,  a branch  which  passes 
between  the  flexor  tendons  and  the  metacarpal  bones,  and 
anastomoses  with  the  Arcus  Profundus.  It  then  generally 
sends  off  a branch  to  the  inner  or  radial  side  of  the  little 
finger;  and  afterwards  three  branches  in  succession,  which 
pass  from  its  convex  side  towards  the  angles  formed  by 
the  fingers.  These  are  called 

The  Digital  Arteries. 

When  they  have  arrived  near  to  the  heads  of  the  first 
phalanges  of  the  fingers,  each  of  these  arteries  divides  into 
two  branches,  one  of  which  passes  along  the  side  of  one  of 
the  fingers  to  its  extremity,  and  the  other  on  the  opposite 
side  of  the  next  finger:  and  in  this  way  they  pass  on  the 
sides  of  all  the  fingers,  except  the  inside  of  the  little  finger 
and  the  outside  of  the  index. 

These  branches  of  the  digital  arteries  are  called  Digito 
Radial  and  Digito  Ulnar  arteries,  according  to  the  sides 


Its  Ramifications  on  the  Hand  and  the  Fingers.  £>73 

of  the  fingers  on  which  they  are  placed.  They  are  situa- 
ted on  the  angle,  if  it  may  be  so  termed,  which  is  formed 
by  the  anterior  and  lateral  surfaces  of  each  finger.  In 
their  course  from  the  basis  to  the  extremity  of  the  finger, 
they  send  off  very  small  transverse  branches,  which  anas- 
tomose with  each  other,  especially  near  the  joints.  Some 
transverse  branches  are  observable  on  the  posterior  as 
well  as  the  anterior  surfaces.  Near  the  extremity  of  each 
finger,  beyond  the  insertion  of  the  flexor  tendon,  the  ex- 
tremities of  these  arteries  ramify  minutely.  Some  of 
these  small  branches  go  to  the  skin,  and  others  anas- 
tomose with  their  fellows  of  the  opposite  side.  Some 
also  go  to  the  back  of  the  fingers.* 

* The  distribution  of  the  radial  and  ulnar  arteries  in  the  hand,  is  very 
different  in  different  subjects. 

Upon  examining-  a large  number  of  injected  preparations  in  Phila- 
delphia, it  was  found  that,  in  a very  small  majority  of  them,  the  ulnar 
artery  formed  an  arcus  sublimis,  whose  branches  extended  as  far  as 
the  ulnar  side  of  the  index,  and  sometimes  beyond  it. 

That,  in  near  a third  of  the  preparations,  the  ulnar  artery  ramified 
without  forming  an  arcus,  and  supplied  only  two  of  the  digital  branches, 
viz.  the  first  two  on  the  ulnar  side.  In  such  cases  the  radial  artery  ge- 
nerally made  up  the  deficiency  of  the  ulnar,  but  in  a few  instances  the 
interosseal  was  extended  on  the  palm  of  the  hand,  and  supplied  the 
radial  side  of  the  middle  finger  and  the  corresponding  side  of  the 
index. 

In  a few  instances  also  the  ulnar  artery  was  still  more  deficient,  a;v! 
the  radial  was  proportionally  extended. 

Vox.  II.  2 M 


274 


Bronchial  Artery* 


SECTION  III. 

Of  the  Branches  %vhich  go  off  between  the  arch  and 
the  great  bifurcation  of  the  AORTA. 

PART  I. 

In  the  Cavity  cif  the  Thorax. 

THE  aorta  sends  branches  to  the  Lungs , to  the  ceso- 
phagus,  and  to  the  parietes  of  the  thorax. 

The  bronchial  Arteries 

Are  the  vessels  which  go  from  the  aorta  to  the  ramifi- 
cations of  the  trachea,  and  the  substance  of  the  lungs. 
They  are  not  large,  and  are  very  irregular  as  to  number 
and  origin. 

In  a majority  of  cases  the  right  lung  is  supplied,  in 
part,  by  a branch  from  the  first  aortic  intercostal  of  that 
side;  while  the  left  lung  receives  two  or  three  branches 
from  the  aorta  directly.  In  some  cases  a large  vessel 
arises  from  the  aorta,  which  divides  into  two  branches, 
one  of  which  goes  to  each  lung. 

The  bronchial  arteries  frequently  send  small  branches 
to  the  posterior  mediastinum,  the  pericardium,  &c. 

Injections  have  shown,  that  there  is  a direct  communi- 
cation between  these  vessels  and  the  branches  of  the 
pulmonary  artery. 

The  Oesophageal  Arteries 

Are  very  small  vessels,  which  generally  arise  from  the 
aorta,  but  sometimes  are  branches  of  the  bronchials  or 


Intercostal  Arteries . 


275 


intercostals  that  are  spent  upon  the  (esophagus.  They 
occur  in  succession,  and  sometimes  are  five  or  six  in 
number.  They  also  send  twigs  to  the  contiguous  parts, 
and  the  lowermost  often  descend  to  the  stomach. 

The  Inferior  Intercostals 

Are  the  arteries  which  proceed  directly  from  the  aorta 
to  the  parietes  of  the  thorax.  Their  name  is  derived  from 
their  position  between  the  ribs.  They  are  ramified  on  the 
intercostal  muscles  and  ribs,  and  on  the  pleura  and  some 
of  the  the  contiguous  parts.  They  are  called  Inferior  or 
Aortic  Intercostals , to  distinguish  them  from  the  superior 
intercostals,  which  are  derived  from  the  subclavian  artery. 
Their  number  varies  from  ten  to  eight,  according  as  the 
superior  intercostals  are  more  or  less  numerous. 

They  originate  in  pairs  on  the  posterior  surface  of  the 
aorta.  The  uppermost  of  them  pass  obliquely  upwards, 
and  the  lowermost  nearly  in  a horizontal  direction,  to 
the  lower  edges  of  those  ribs  to  which  they  are  appro- 
priated. They  meet  the  rib  near  its  tubercle,  or  place  of 
junction  with  the  transverse  process  of  the  vertebra,  and 
then  proceed  forward,  between  the  internal  and  external 
intercostal  muscles,  in  a superficial  but  large  groove, 
which  is  generally  to  be  found  on  the  interior  margin  of 
the  lower  surface  of  the  rib.*  There  is  necessarily  a differ- 
ence in  the  length  of  the  right  and  left  intercostals,  owing 
to  the  position  of  the  aorta,  which  is  rather  on  the  left  of 
the  spine.  In  consequence  of  this  circumstance,  the  oeso- 
phagus is  anterior  to,  and  also  in  contact  with  those  of 
the  right  side. 

They  generally  send  off  an  important  branch,  called 
the  Dorsal , which  arises  near  their  origin,  and,  passing 


* See  Vol.  I.  page  89. 


276  General  Account  of  the 

backwards,  sends  ramifications  to  the  muscles  of  the 
back.  From  this  dorsal  branch  also  proceeds  a ramifica- 
tion, which  enters  the  spinal  cavity,  and  is  spent  upon  its 
membrane  and  upon  the  medulla  spinalis. 

After  the  intercostals,  in  their  progress  forward, 
have  passed  beyond  the  middle  of  the  ribs,  they  send  off 
a branch,  which  generally  proceeds  very  near  to  the  upper 
side  of  the  lower  rib.  The  main  trunk  generally  leaves 
the  lower  edge  of  the  rib  when  it  has  arrived  within  one 
third  of  the  length  of  the  bone  from  its  anterior  extre- 
mity. It  then  generally  divides  into  several  branches, 
some  of  which  are  spent  upon  the  pleura,  and  others  on 
the  intercostal  and  the  contiguous  muscles. 

According  to  the  situation  of  the  different  intercostals, 
some  of  their  ramifications  communicate  with  those  of 
the  internal  and  external  mammaries,  of  the  phrenic,  the 
lumbar,  or  the  epigastric  arteries. 

PART  II. 

, In  the  Cavity  of  the  Abdomen. 

The  AORTA  passes  into  the  cavity  of  the  abdomen 
between  the  crura  of  the  diaphragm,  as  has  been  already 
mentioned.  In  its  course  from  the  crura  to  its  great  bi- 
furcation, it  sends  off  one  pair  of  small  arteries,  called 
Phrenic , to  the  diaphragm.  Three  single  arteries,  the 
C CELIAC,  the  SUPERIOR,  and  the  INFERIOR 
mesenteric,  to  the  viscera  of  the  abdomen.  A pair  of 
large  arteries,  the  EMULGENTS,  to  the  kidneys,  with 
several  that  are  very  small  to  their  appendages;  as  the 
Spermatics , Capsular , the  Ureteric , and  the  Adipose.  In 
addition  to  these,  there  is  one  pair  of  small  arteries  that 
go  to  the  testicles,  or  to  the  ovaria  and  the  uterus,  and 
four  or  five  pair,  called  lumbar  arteries,  that  go  off 


Arteries  of  the  Abdomen.  277 

laterally,  like  the  intercostals,  to  the  parietes  of  the  abdo- 
men, and  to  the  muscles,  &c.,  on  the  back,  which  are 
contiguous  to  them. 

The  phrenic  Arteries 

Are  ramified  on  the  concave  surface  of  the  diaphragm, 
and  are  almost  always  two  in  number;  they  are  denomi- 
nated right  and  left  from  their  position.  They  commonly 
originate  separately  from  the  aorta,  but  sometimes  they 
arise  in  a common  trunk  which  soon  divides.  In  some 
instances  they  are  derived  from  the  cceliac.  In  a few  cases 
the  aorta  furnishes  one,  and  the  cceliac  the  other.  Each  of 
the  phrenic  arteries  commonly  crosses  the  crus  of  the 
diaphragm  on  its  respective  side,  and  proceeding  laterally, 
in  a circular  direction,  often  ramifies  so  as  to  form  an 
internal  and  an  external  branch.  Each  of  them  generally 
sends  branches  to  the  cardia  or  oesophagus,  to  the  glandules 
renales,  and  other  contiguous  parts. 

The  CCELIAC  Artery 

Is  the  first  great  branch  given  off  by  the  aorta  in  the 
abdomen,  and  is  distributed  almost  entirely  to  the  stomach, 
the  liver,  and  the  spleen.  It  projects  from  the  anterior 
part  of  the  aorta  so  as  to  form  a right  angle  with  it,  and 
is  of  course  nearly  horizontal  when  the  body  is  erect. 

The  main  trunk  of  this  great  artery  is  so  remarkably 
short,  that  it  has  been  compared  to  the  stump  of  a tree: 
for  at  the  distance  of  half  an  inch  from  its  origin,  it 
generally  divides  into  three  branches,  which  pass  to  the 
stomach,  the  liver,  and  the  spleen,  and  are,  therefore, 
denominated  the  gastric  or  coronary,  the  HEPATIC 
and  the  SPLENIC  arteries. 

The  first  mentioned  branch  may  be  called 


278 


distribution  aj 


The  SUPERIOR  CORONARY  Or  GASTRIC  ARTERY, 

To  distinguish  it  from  other  branches,  soon  to  be  describ- 
ed. It  is  commonly  in  the  center  of  the  three  great  rami- 
fications of  the  cceliac,  and  is  also  the  smallest  of  them.  It 
proceeds  from  its  origin  to  the  upper  orifice  of  the  stomach 
or  cardia,  and  continues  thence  along  the  lesser  curvature 
of  that  viscus,  until  it  approaches  near  to  the  pylorus.  In 
this  course  it  sends  branches  to  the  oesophagus,  which 
frequently  inosculate  with  the  oesophageal  arteries.  It  also 
furnishes  branches  to  the  cardia,  which  partially  surround 
it;  and  on  this  account,  the  artery  has  been  called  Co- 
ronary. Some  of  these  last  mentioned  branches  are  often 
continued  on  the  great  extremity  of  the  stomach,  and 
anastomose  with  those  ramifications  of  the  splenic  artery, 
called  Vasa  Brevia. 

It  continues  on  the  lesser  curvature  between  the  laminae 
of  the  small  omentum,  and  sends  off  successively  branches 
which  pass  between  the  peritoneal  and  muscular  coats, 
and  are  distributed  to  the  anterior  and  posterior  surfaces 
of  the  stomach,  communicating  with  the  branches  of  the 
inferior  gastric  arteries,  soon  to  be  described.* 

The  HEPATIC  Artery 

Proceeds  from  the  great  ramification  of  the  cceliac  to  the 
transverse  fissure  of  the  liver  called  the  Portce , in  which 
it  generally  divides  into  two  branches.  In  this  course  it 
very  frequently  sends  off  an  artery  to  the  pylorus,  which 
ramifies  about  the  small  extremity  of  the  stomach,  and 
often  inosculates  with  some  of  the  branches  of  the  superior 

* This  artery  sometimes  sends  a branch  to  the  liver.  When  this  is 
the  case,  it  is  always  very  large. 


the  Ccdiac  Artery . .27 9 

coronary.  This  branch  is  called  the  Pylorica,  and  some- 
times it  arises  from  the  artery  next  to  be  mentioned. 

The  GASTRICA  INFERIOR  DEXTRA, 

Which  also  generally  originates  from  the  main  trunk 
of  the  hepatic,  but  sometimes  from  one  of  its  branches.  It 
is  an  artery  of  considerable  size,  which  proceeds  along  the 
great  curvature  of  the  stomach,  from  the  pylorus  towards 
the  great  extremity,  between  the  laminae  of  the  auterior 
portion  of  the  omentum,  and  distributes  its  ramifications 
to  both  sides  of  the  stomach,  and  also  to  the  Omentum.  In 
its  progress  from  the  hepatic  artery  to  the  stomach,  it 
sends  off  branches  to  the  Duodenum , and  to  the  right  end 
of  the  Pancreas. 

The  two  great  branches  into  which  the  HEPATIC 
artery  divides  are  denominated  right  and  left,  from 
the  lobes  of  the  viscus,  to  which  they  are  respectively 
appropriated.  The  right  branch  is  the  largest.  Before  it 
penetrates  the  substance  of  the  liver,  it  sends  off  a branch 
to  the  gall  bladder,  called  the  Cystic  Artery. 

The  branches  of  the  hepatic  artery  ramify  very  minutely 
in  the  liver,  as  has  been  stated  in  the  account  of  that  organ. 

The  last  great  branch  of  the  coeliac  is 

The  SPLENIC  Artery , 

Which  is  generally  supposed  to  be  larger  than  the  hepatic 
in  adults,  although  it  is  less  in  children.  It  proceeds  in  a 
transverse  direction  from  its  origin  to  the  spleen:  its 
course  is  not  straight,  but  meandering  or  serpentine.  It 
is  situated  behind  and  above  the  pancreas,  and  passes 
along  the  groove  in  the  upper  edge  of  that  viscus.  In  its 
progress,  it  sends  off  many  small  branches,  and  one  that 
is  of  considerable  size,  to  the  Pancreas.  It  also  sends 


280 


Distribution  of  the  Splenic 

one  branch  to  the  left  extremity  of  the  stomach,  which 
arises  commonly  from  the  main  trunk,  but  sometimes 
from  the  ramifications,  which  are  soon  to  be  mentioned. 
This  branch,  which  is  called 

The  GASTRICA  INFERIOR  SINISTRA, 

Is  sometimes,  but  not  often,  very  large:  Its  course  is 
from  left  to  right.  It  is  situated  between  the  laminae  of  the 
anterior  portion  of  the  omentum.  It  sends  some  small 
branches  to  the  omentum,  and  others  which  are  larger 
and  more  numerous,  to  both  sides  of  the  stomach.  Some 
of  these  last  mentioned  anastomose  with  the  ramifications 
of  the  gastrica  dextra,  which  come  from  the  hepatic. 

When  the  SPLENIC  artery  approaches  near  to  the 
spleen,  it  divides  into  four,  five,  or  six  branches,  each  of 
which  penetrates  into  that  viscus  by  a distinct  foramen, 
and  then  ramifies  in  the  manner  described  in  the  account 
of  the  structure  of  the  spleen.* 

Either  from  the  splenic  artery,  or  from  these  ramifica- 
tions, four  or  five  branches  pass  to  the  large  extremity  of 
the  stomach,  and  ramify  there,  communicating  with  the 
vessels  already  described. — These  arteries  have  received 
great  attention  from  physiologists,  and  are  denominated 
Vasa  Brevia. 

The  SUPERIOR  MESENTERIC, 

Which  is  the  second  great  branch  given  off  in  the  abdomen 
by  the  aorta,  is  not  very  different  in  size  from  the  cceliac, 
and  originates  about  half  an  inch  below  it.  It  is  distributed 
to  the  small  intestines;  to  that  portion  of  the  great  itites- 

* It  frequently  happens  that  the  splenic  artery  divides  only  into  two 
or  three  branches,  and  they  subdivide  so  as  to  form  five  or  six,  which 
penetrate  the  spleen 


and  the  Superior  Mesenteric  Arteries.  231 

tinfe,  which  is  situated  on  the  right  side  of  the  abdomen; 
atid  to  the  arch  of  the  colon.  From  its  origin  it  proceeds 
downwards,  under  the  pancreas,  and  over  the  lower  por- 
tion of  the  duodenum,  to  the  commencement  of  the  me- 
sentery. When  it  has  arrived  between  the  laminae  of 
that  membrane,  it  descends  in  a direction  which  cor- 
responds with  that  of  the  root  of  the  mesentery,*  and 
forms  a gentle  curve,  with  its  convexity  directed  towards 
the  intestines.  It  necessarily  diminishes  as  it  descends,  and 
generally  terminates  by  anastomosing  with  one  of  its  own 
branches. — This  great  artery  sends  off  some  very  small 
ramifications  to  the  pancreas  and  the  duodenum,  while  it 
is  in  their  vicinity.  It  also  sends  two  or  three  branches  to 
the  transverse  part  of  the  colon,  to  the  right  portion  of 
the  colon,  to  the  beginning  of  the  great  intestine,  and  the 
Contiguous  portion  of  the  ileon.  These  branches  are  com- 
monly termed  the  colica  media,  colica  deJitra,  and 
ileo  colica.  From  the  convex  side  of  the  curve,  the 
SUPERIOR  MESENTERIC  sends  off  the  important 
branches  Which  pass  between  the  laminae  of  the  mesentery, 
and  supply  the  Small  Intestines.  These  branches  are  numer- 
ous, and  many  of  their  ramifications  anastomose  with  each 
other  so  as  to  form  arches.  From  these  arches  go  off  other 
branches,  which  anastomose  again  with  some  of  similar 
origin;  and  this  process  is  repeated  successively  several 
times,  so  that  a net-work  of  bloodvessels  seems  to  be 
formed  on  the  mesentery.  From  the  mesentery  the  small 
ramifications  are  continued  in  great  numbers  to  the  intes- 
tines. Some  of  them  anastomose  with  each  other  on  the 
coats  of  the  intestine;  but  an  immense  number  of  minute 


VoL.  II. 


See  Vol.  II.  page  11. 

2N 


282  Distribution  of  the  Inferior  Mesenteric. 

arteries  are  continued  to  the  villous  coat,  so  that,  when 
they  are  successfully  injected,  the  surface  of  that  coat  ap- 
pears uniformly  coloured  by  the  injection.* 

The  INFERIOR  MESENTERIC  Artery 
Does  not  go  off  from  the  aorta  next  in  order  after  the 
superior  mesenteric,  but  succeed?  it  immediately  on  the 
intestines,  and  continues  the  arterial  ramifications  to  the 
left  portion  of  the  colon , to  which  the  branches  of  the 
superior  mesenteric  do  not  extend. 

This  artery  arises  between  the  origin  of  the  emulgents, 
and  the  great  bifurcation  of  the  aorta,  and  proceeds 
downwards,  inclining  to  the  left,  but  keeping  near  to  the 
aorta.  There  are  generally  three  branches  distributed  to 
the  left  portion  of  the  colon,  which  arise  from  this  artery, 
either  separately,  or  by  a common  trunk  which  soon 
divides.  It  frequently  happens,  that  one  of  these  arteries 
arises  separately,  and  two  by  a common  trunk.  These  are 
called  the  left  colic  arteries;  and  are  also  sometimes 
denominated,  from  their  position,  superior,  middle,  and 
inferior.  The  superior  generally  anastomoses  with 
that  branch  of  the  superior  mesenteric,  which  is  called 
colica  media,  and  forms  a remarkable  arch,  called  the 
Great  Mesocolic  Arch.  The  ramifications  of  the  other 
branches  frequently  anastomose  with  each  other,  and  are 
finally  spent  upon  the  left  portion  of  the  colon. 

The  main  trunk,  diminished  by  sending  off  these 
branches,  but  still  of  considerable  size,  runs  downwards 
on  the  posterior  part  of  the  intestine  rectum,  between 

* See  the  account  of  the  termination  of  these  arteries,  at  page  107 
of  this  volume. 


Arteries  of  the  Kidneys  and  Renal  Glands.  283 

that  intestine  and  the  sacrum,  where  it  often  divides  into 
two  branches,  which  continue  near  to  the  termination  of  the 
rectum.  From  them  proceed  many  ramifications  that  are 
spent  upon  the  rectum.  Some  of  these  ramifications  anas- 
tomose with  each  other,  and  others  with  the  ramifications 
of  the  hsemorrhoidal  artery,  $oon  to  be  mentioned. 

The  EMULGENT  or  RENAL  Arteries 
Are  the  large  vessels  which  pass  from  the  aorta  to  the 
kidneys.  They  arise  between  the  superior  and  inferior 
mesenteries,  one  on  each  side;  and  proceed  in  a direction 
which  is  nearly  rectangular  to  the  aorta.  The  right  emulgent 
artery  is  necessarily  longer  than  the  left,  and  it  generally 
passes  behind  the  vena  cava.  When  they  approach  near 
the  concave  edges  of  the  kidneys,  each  emulgent  com- 
monly divides  into  three  or  four  branches,  which  pass 
into  the  fissure  of  that  organ,  and  ramify  in  the  manner 
described  in  the  account  of  it.  Sometimes  two  arteries 
proceed  from  the  aorta  to  the  kidney:  but  this  is  not 
a frequent  occurrence. 

The  Capsular  Arteries 

Are  the  small  vessels  which  pass  to  the  glandulae  renales. 
There  are  almost  always  several  of  them  appropriated  to 
each  gland.  They  often  arise  on  each  side  from  the  cceliac 
artery,  the  aorta,  and  the  emulgent. 

The  Adipose  Arteries 

Supply  the  adipose  substance  surrounding  the  kidneys. — . 
There  are  several  of  them  on  each  side,  and,  like  the  last 
mentioned  arteries,  they  are  very  small,  and  arise  from 
several  sources  as  well  as  the  aorta. 

The  testicles  and  ovaria  are  supplied  by  the 


284 


Spermatic  Arteries. 


Spermatic  Arteries , 

Which  are  very  remarkable  for  their  great  length  and 
small  diameter.  In  a majority  of  cases  these  vessels  arise 
from  the  anterior  surface  of  the  aorta,  a little  below  the 
emulgents:  but  it  often  happens  that  the  left  spermatic 
arises  from  the  emulgent  on  that  side.  They  also  some- 
times arise  from  other  neighbouring  arteries.  It  has  been 
observed  when  thev  arise  from  the  aorta,  that  the  origin 
of  one  of  them  is  generally  higher  than  that  of  the  other. 

They  pass  downwards,  so  as  to  form  an  acute  angle 
with  the  aorta,  and  proceed  behind  the  peritoneum,  and 
before  the  psoas  muscle  and  ureter.  While  this  artery  is 
in  contact  with  the  psoas  muscle,  it  meets  with  the  rami- 
fications of  the  spermatic  vein , and,  in  its  progress  to  the 
abdominal  ring,  also  joins  the  spermatic  cord.  In  this 
course  it  sends  olf  some  very  small  twigs  to  the  con- 
tiguous parts,  and  others  that  anastomose  with  similar 
ramifications  from  tne  mesenteric,  epigastric,  &c.  Before 
it  arrives  at  the  testicle,  it  divides  into  several  branches, 
two  of  which  generally  go  to  the  epididymis,  and  the 
others  penetrate  the  upper  and  back  part  of  the  tunica 
albuginea. 

The  Spermatic  Arteries  in  the  Female , 

Instead  of  passing  to  the  abdominal  ring,  proceed  between 
the  laminae  of  the  broad  ligaments,  and  send  branches  to 
the  ovaria,  which,  in  some  cases,  may  be  traced  to  the 
vesicles.  They  also  send  branches  to  the  fallopian  tubes 
and  uterus,  and  to  the  round  ligaments.  Those  which  are 
on  the  opposite  sides  of  the  uterus,  anastomose  with  each 
other  and  with  the  branches  of  the  hypogastric  arteries. 

The  lumbar  regions  are  supplied  with  arteries,  which 
originate,  like  the  intercostals,  from  the  posterior  part  o! 


Arteries  above  and  at  the  bifurcation  of  the  Aorta . 285 

the  aorta  between  the  thorax  and  pelvis.  There  are  four 
or  five  of  these  vessels  on  each  side,  and  they  are 
denominated 

The  Lumbar  Arteries: 

They  pass  between  the  spine  and  the  psoas  muscles,  and 
send  branches  to  the  spinal  cavity,  to  the  muscles  of  the 
lumbar  regions,  and  the  abdominal  muscles.  They  anasto- 
mose with  the  internal  mammary,  the  epigastric,  the  cir- 
cumflex of  the  ileum,  &c. 

A small  artery  passes  off"  singly  from  the  posterior  part 
of  the  aorta  at  its  bifurcation,  which  is  called 

The  Middle  Sacral  Artery. 

It  proceeds  down  the  middle  of  the  sacrum  to  the  os 
coccygis,  and  sends  off  lateral  branches,  which  are  spent 
upon  the  contiguous  parts,  and  inosculate  with  the  arteriae 
sacrse  laterales. 

SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the 
Great  Bifurcation  of  the  Aorta. 

The  PRIMITIVE  ILIACS 
Form  an  acute  angle  with  each  other.  They  proceed 
downwards  behind  the  peritoneum,  very  near  the  margin 
of  the  pelvis,  without  sending  off  any  branch  of  im  portance. 
At  the  junction  of  the  sacrum  with  the  ossa  ilea,  they 
divide  into  two  great  branches:  the  INTERNAL  ILIAC, 
or  HYPOGASTRIC , which  descends  into  the  pelvis;  and 
the  EXTERNAL  ILIAC , which  passes  under  the  criJral 
arch  to  the  lower  extremity. 


286  General  Account  of  the  Internal  Iliac. 

The  INTERNAL  ILIAC , or  HYPOGASTRIC , 

Is  distributed,  in  part,  to  the  viscera  of  the  pelvis  and  the 
organs  of  generation,  and  also  to  the  large  muscles  ex- 
terior to  the  pelvis:  it  is,  therefore,  very  large,  although 
not  quite  equal  to  the  EXTERNAL  ILIAC. 

It  has  already  been  mentioned,  that  in  the  foetal  state, 
this  vessel  appeared  to  continue  in  a curved  direction 
from  its  origin  to  the  lower  part  of  the  side  of  the  bladder, 
and  from  thence  to  the  umbilicus,  under  the  denomination 
of  the  Umbilical  Artery.  From  the  convex  side  of  this 
curve  the  different  branches  of  the  internal  iliac  go  off.  In 
the  foetal  state  they  are  very  small  in  proportion  to  the 
umbilical  artery;  but  as  the  artery  becomes  ligamentous, 
these  branches  increase  in  size. 

In  the  adult,  the  arrangement  of  these  vessels  is  very 
different.  The  INTERNAL  ILIAC  generally  divides 
into  two  great  branches:  the  gluteal,  which  passes 
through  the  sacro  sciatic  notch,  and  ramifies  on  the  ex- 
terior and  upper  part  of  the  os  ileum;  and  the  ischiatic, 
which  passes  downwards  on  the  outside  of  the  tuberosity 
of  the  ischium. 

The  first  of  these  large  ramifications  passes  outofthe  pel- 
vis above  the  pyriform  muscle,  and  the  last  of  them  below 
it.  Several  smaller  arteries  arise  from  these  branches  near 
their  origin,  or  from  the  main  trunk  of  the  internal  iliac, 
which  are  distributed  to  the  different  parts  of  the  pelvis; 
and  one  important  branch  of  the  ischiatic,  called  the 
pudic,  proceeds  downward  on  the  inside  of  the  tuberosity 
of  the  ischium. 

The  first  of  the  smaller  branches  which  the  internal 
iliac  commonly  sends  off,  is  called  the 


Smaller  Branches  of  the  Internal  Iliac. 


287 


Ileo  Lumbalis: 

It  sometimes  arises  from  the  gluteal  artery,  and  sometimes 
from  the  main  trunk  of  the  internal  iliac.  It  passes  out- 
wards under  the  psoas  muscle,  and  suddenly  divides  into 
two  branches.  One  of  them  proceeds  upwards,  and  is 
distributed  in  the  lumbar  region,  while  the  other  ramifies 
on  the  iliacus  internus  muscle,  and  is  spent  on  the  con- 
tiguous parts. 

There  are  also  two  or  three  small  arteries  called 
Arteries  Sacrce  Later  ales. 

Which  sometimes  arise  singly,  and  sometimes  in  common, 
from  the  great  trunk.  They  also  occasionally  originate 
from  the  gluteal  artery.  These  vessels  enter  the  anterior 
foramina  of  the  os  sacrum,  to  be  distributed  on  the  cauda 
equina  and  the  membranes  which  invest  it.  Some  of  their 
ramifications  anastomose  with  branches  of  the  sacra  media 
and  other  contiguous  arteries. 

On  the  anterior  side  of  the  internal  iliac,  near  the 
origin  of  the  above  mentioned  vessels,  a ligament  which 
was  originally  the  umbilical  artery,  goes  off  to  the  side 
of  the  bladder,  and  continues  from  thence  to  the  umbilicus. 
Sometimes  it  continues  pervious  for  a short  distance,  and 
then  small  branches  pass  from  it  to  the  bladder. 

In  the  female  it  also  sends  small  branches  to  the  uterus 
and  vagina. 

In  addition  to  these  Vesical  Arteries  derived  from  the 
umbilicals,  there  are  other  branches  distributed  to  the 
bladder,  which  arise  very  differently,  in  different  subjects, 
from  branches  which  are  soon  to  be  described,  as  the  hse- 
morrhoidal,  pudic,  &c. 


288  Smaller  Branches  of  the  Internal  Iliac. 

From  the  anterior  side  of  the  internal  iliac,  or  from  one 
of  its  great  branches,  an  artery  often  arises  which  passes 
out  of  the  pelvis  through  the  aperture  in  the  margin  of  the 
ligamentous  membrane  which  closes  the  foramen  thyroi- 
deum  of  the  os  innominatum;  this  is  called  the 

Obturator  Artery. 

This  vessel,  while  it  is  in  the  pelvis,  often  sends  small 
branches  to  the  bladder  and  its  appendages,  and  to  the 
obturator  internus  muscle.  After  it  passes  out  of  the 
pelvis,  it  frequently  divides  into  branches;  some  of  which 
are  spent  on  the  obturator  externus,  and  the  contiguous 
muscles,  and  others  go  to  the  hip  joint.  The  origin  of  this 
artery  is  variable.  Most  commonly  it  arises  from  the  inter- 
nal iliac,  but  often  from  the  ischiatic,  and  sometimes  from 
the  gluteal.  In  some  instances  it  originates  in  a way  that 
is  particularly  interesting  when  the  operation  for  crural 
hernia  is  to  be  performed,  viz.  from  the  epigastric  artery , 
soon  to  be  described:  for  in  this  case  the  obturator  artery 
sometimes  nearly  surrounds  the  neck  of  the  hernial  sac.* 
A small  artery  passes  from  the  internal  iliac  or  one  of 
its  branches,  to  the  rectum,  which  is  called  the 

Middle  Hemorrhoidal , 

From  its  situation  between  the  branches  which  are  sent  to 
that  intestine  from  the  inferior  mesenteric,  and  those  which 
go  to  it  from  the  pudic.  This  artery  is  spent  upon  that  part 
of  the  rectum,  which  is  above  and  in  contact  with  the 

* See  Astley  Cooper’s  great  work  on  Hernia,  Vol.  I. 

There  is  reason  to  believe  that  this  position  of  the  artery  occurs  more 
frequently  than  has  been  supposed. 


289 


Larger  Branches  of  the  Internal  Iliac. 

sphincter.  It  sends  branches  to  the  prostate  and  vesiculag 
seminales  in  males,  and  the  vagina  and  bladder  in  females. 
In  females  there  is  a peculiar  artery, 

The  Uterine , 

Which  originates  either  from  the  internal  iliac,  near  the 
origin  of  the  ischiatic,  or  from  one  of  its  branches.  It  passes 
between  the  laminae  of  the  broad  ligaments  to  the  cervix 
uteri,  and  penetrates  the  texture  of  that  organ.  The  size 
of  this  vessel  varies  with  the  varying  size  of  the  uterus. 

The  GLUTEAL  or  POSTERIOR  itlAC  Artery , 

One  of  the  two  great  branches  of  the  internal  iliac, 
proceeds  exteriorly  through  the  sciatic  notch  above  the 
pyriform  muscle,  very  near  the  edge  of  the  bone.  On 
the  outside  of  the  ilium  it  generally  divides  into  two 
branches,  one  of  which  ramifies  between  the  gluteus 
medius  and  minimus,  and  the  other  between  the  medius 
and  maximus.  It  is  principally  spent  upon  these  muscles, 
and  sends  branches  to  the  contiguous  parts. 

The  ISCHIATIC  Artery , 

The  other  great  branch  of  the  internal  iliac,  passes  through 
the  sciatic  notch  belozv  the  pyriform  muscle,  and  proceeds 
downwards,  between  the  great  trochanter  of  the  os  femoris 
and  the  tuberosity  of  the  ischium,  under  the  gluteus 
maximus  muscle.  Soon  after  its  origin,  it  commonly  sends 
off  a considerable  branch,  the  Arteria  Pudica , which  also 
passes  downwards:  it  then  continues  its  course  as  above 
mentioned,  and  its  principal  branches  are  distributed  to 
the  gluteus  maximus  and  the  muscles  of  the  upper  and 
back  part  of  the  thigh,  while  its  smaller  branches  go  to 
Vol.  II.  2 O 


290  Puclic  Artery. 

the  os  sacrum  and  coccyx,  and  the  contiguous  small 
muscles.  * 

The  PUDICA  INTERNA, 

As  has  been  just  mentioned,  is  often  a branch  of  the 
ischiatic  artery,  but  sometimes  originates  immediately 
from  the  internal  iliac.  It  proceeds  downwards  and  in- 
wards, diverging  from  the  ischiatic,  and  passing  between 
the  two  sacro  sciatic  ligaments  to  the  interior  side  of  the 
tuberosity  of  the  ischium,  whence  it  continues  on  the 
inside  of  the  crus  of  the  os  ischium  and  pubis  until  it 
approaches  the  symphysis,  when  it  generally  divides  into 
three  branches,  which  are  spent  upon  the  organs  of  gene- 
ration, from  which  circumstance  the  name  of  this  artery 
is  derived. 

One  or  more  branches  from  it  also  pass  to  the  lower 
part  of  the  rectum  and  sphincter  ani,  and  are  called  the 
Lorver  Hcemorrhoidal  Arteries. 

In  its  course  it  sends  off  many  small  branches  to  the 
contiguous  parts;  one  of  which,  called  the  Perineal , leaves 
it  near  the  transversus  perinei  muscle,  and  passes  between 
that  muscle  and  the  skin,  and  between  the  bulb  of  the 
urethra  and  the  crus  of  the  penis,  to  the  scrotum. 

When  the  pudic  has  arrived  near  the  bulb  of  the  urethra 
it  sends  a branch  into  it,  which  is  continued  into  the  corpus 
spongiosum  urethrae,  and  ramifies  there  minutely. 

At  the  symphysis  of  the  pubis,  it  sends  off  a second 
branch,  which  passes  to  the  back  of  each  crus,  and,  pro- 
ceeding along  it,  parallel  to  its  fellow,  terminates  in  the 
glans  penis:  in  this  course  it  sends  branches  to  the  elastic 
coat,  to  the  integuments,  and  to  the  prepuce.  This  vessel 
is  called  the  Afteria  Dorsalis. 

The  main  trunk  of  the  pudic  artery  then  penetrates  the 
corpus  cavernosum,  and  proceeds  through  it  in  a straight 


External  Iliac . Branches  of  the  External  Iliac.  291 

direction.  Its  ramifications  appear  to  be  distributed  through 
the  internal  structure  of  the  corpus  cavemosum,  and  some 
of  them  extend  through  the  septum  to  the  other  side,  while 
others  pass  to  the  corpus  spongiosum  urethrae. 

The  EXTERNAL  ILIAC , 

The  great  artery  of  the  lower  extremity,  appears  soon 
after  birth,  like  a continuation  of  the  primitive  iliac,  and 
proceeds  along  the  brim  of  the  pelvis  behind  the  peri- 
toneum, to  Poupart’s  ligament  or  the  crural  arch,  under 
which  it  passes. 

The  psoas  muscle  is  at  first  in  contact  with  it  on  the  out- 
side, and  the  internal  iliac  vein  on  the  inside.  As  it  passes 
under  Poupart’s  ligament,  it  is  immediately  anterior  to 
the  psoas  and  iliacus  internus  muscles  where  they  are 
united,  and  the  crural  nerve  is  exterior  to  it.  Before  it 
arrives  at  the  lower  edge  of  Poupart’s  ligament,  it  sends 
off 

The  Epigastric  Artery , 

Which  arises  on  its  internal  side,  and  proceeds  down- 
wards and  inwards  about  half  an  inch,  then  it  turns 
upwards  and  inwards,  and  continues  in  that  direction  for 
a small  distance,  after  which  its  course  is  less  oblique.  It 
passes  between  the  peritoneum  and  the  abdominal  muscles, 
behind  the  spermatic  cord,  and  the  round  ligament  in 
females. 

It  generally  changes  its  oblique  direction  after  passing 
about  two  inches,  and  then  proceeds  in  contact  with  the 
rectus,  and  very  near  its  external  edge.  Its  ramifications 
are  expended  upon  the  anterior  parietes  of  the  abdomen; 
and,  after  it  has  arrived  as  high  as  the  umbilicus,  it  com- 


292  General  Account  of  the  Femoral  Artery. 

monly  divides  into  branches,  which  often  inosculate  with 
the  ramifications  of  the  internal  mammary.* 

An  artery,  which  is  rather  smaller  than  the  epigastric, 
arises  nearly  opposite  to  it,  but  rather  lower,  from  the 
external  side  of  the  external  iliac.  It  is  called 

The  Circumflex  Artery  of  the  Os  Ilium , 

And  proceeds  upwards  and  outwards  to  the  upper  margin 
of  the  os  ilium,  along  which  it  continues  very  near  to  the 
spine.  It  is  distributed  principally  to  the  abdominal  mus- 
cles, to  the  iliacus  internus  and  the  psoas,  and  the  parts 
contiguous. 

The  artery  of  the  lower  extremity,  after  passing  under 
Poupart’s  ligament,  takes  the  name  of 

FEMORAL  Artery , 

And  proceeds  downwards  in  a direction  so  spiral,  that 
although  it  is  in  front  at  the  upper  part  of  the  thigh,  it  is 
completely  behind  at  the  lower  part.  It  sends  branches  to 
the  muscles  of  the  thigh,  as  the  aorta  does  to  the  viscera 
of  the  abdomen,  viz.  by  a few  large  vessels  which  extend 
and  ramify  to  a great  distance  among  them. 

The  situation  of  the  adductor  muscles,  and  their  attach- 
ment to  the  os  femoris,  is  such,  that  the  artery  in  this 
course  must  necessarily  perforate  their  common  tendon, 
which  it  does  at  the  distance  of  one  third  of  the  length  of 
the  bone  from  its  lower  end.  The  aperture  in  this  tendon 
corresponds  precisely  with  the  general  course  of  the 

* Several  respectable  surgeons  have  been  taught  by  experience, 
that  when  the  abdomen  is  distended  by  ascites,  the  position  of  the 
epigastric  artery  is  so  much  altered,  that  it  will  sometimes  be  found  in 
the  middle  of  the  oblique  line,  which  extends  from  the  umbilicus  to 
.the  superior  anterior  spine  of  the  ileum. 


Profunda  and  Circumflex  branches  of  the  Femoral.  293 

artery;  and  before  the  artery  enters  this  perforation,  it 
is  on  the  internal  side  of  the  bone;  after  it  has  passed  the 
perforation,  it  is  on  the  posterior  side  of  it.  After  passing 
through  the  tendon  of  the  adductors,  it  is  denominated 
The  Popliteal  Artery , and  it  retains  this  name  until  it 
divides. 

It  then  proceeds  downwards,  being  very  near  the  bone, 
and  between  the  tendons  of  the  flexors  of  the  leg,  covered 
by  the  great  nerve  of  the  lower  extremity,  and  very  often 
also  by  the  vein.  After  crossing  the  articulation  of  the 
knee,  when  it  is  between  the  heads  of  the  gastroc  nemii 
muscles,  at  the  lower  edge  of  the  popliteus  muscle,  it 
divides  into  the  anterior  tibial  and  the  common  trunk  of 
the  peroneal  and  posterior  tibial  arteries. 

The  FEMORAL  artery,  soon  after  emerging  from 
Poupart’s  ligament,  sends  off  very  small  branches  to 
the  inguinal  glands,  and  other  contiguous  parts.  It  also 
sends  off  the 

External  Pudics , 

Which  are  two  or  three  small  arteries  that  are  generally 
spent  upon  the  Scrotum  in  males  and  the  Labia  Pudendi 
in  females. 

About  two  inches  below  Poupart’s  ligament,  the  great 
branch,  which  has  been  called  the  muscular  artery  of  the 
thigh,  leaves  it.  This  vessel  is  commonly  denominated 

ARTERIA  PROFUNDA. 

It  arises  from  the  back  part  of  the  trunk  of  the  femoral, 
and  passes  downwards  and  backwards,  in  a way  that  has 
been  compared  to  the  separation  of  the  internal  iliac  from 
the  external.  Very  soon  after  its  origin,  it  sends  off"  two 
branches,  which  proceed,  one  on  the  internal,  and  the 
other  on  the  external  side  of  the  thigh,  and  are  called  the 


294  Blanches  of  the  Profunda  and  the  Femoral. 

circumflexa  interna  and  externa.  It  then  passes  downwards 
behind  the  trunk  of  the  femoral,  and  sometimes  very- 
near  it,  on  the  adductor  muscles,  and  finally  divides  into 

branches,  which  are  called  the  Perforating. 

* 

The  External  Circumflex 

Sometimes  arises  from  the  femoral,  but  most  commonly  is 
a branch  of  the  profunda,  as  above  stated.  It  passes  under 
the  rectus  and  tensor  vagina  femoris  towards  the  great 
trochanter,  and  generally  divides  into  two  branches,  one 
of  which  continues  in  the  transverse  direction,  and  sends 
branches  to  the  upper  and  back  part  of  the  thigh,  and  the 
parts  contiguous  to  the  joint;  while  the  other  descends  in 
the  course  of  the  rectus  femoris  muscle,  and  some  of  itjs 
ramifications  extend  near  to  the  outside  of  the  knee. 

The  Internal  Circumflex 

Is  often  smaller  than  the  other.  It  generally  passes  be- 
tween the  psoas  and  the  pectineus  muscles,  and  continues 
round  the  thigh  towards  the  lesser  trochanter.  Its  ramifi- 
cations are  expended  on  the  upper  portions  of  the  adduc- 
tor muscles  and  the  muscular  parts  contiguous  to  the 
lesser  trochanter.  It  also  sends  branches  to  the  articulation. 

The  Perforating  Arteries 

Are  two  or  three  ramifications  of  the  profunda,  which 
pass  through  the  adductor  muscles,  and  are  expended 
upon  the  flexor  muscles  on  the  back  of  the  thigh.  Some 
of  the  terminating  branches  of  the  profunda  itself  are  also 
called  perforating  arteries. 

The  next  branch  of  importance  which  is  sent  off  by  the 
FE MORAL  artery,  leaves  it  before  it  enters  the  aperture 
in  the  tendon  of  the  adductors,  and  is  called 


Branches  about  the  Haw. 


395 


The  Anastomotic  Artery. 

This  vessel  soon  inclines  downwards.  Its  ramifications 
extend  into  the  vastus  internus  muscle;  some  of  them 
follow  the  tendon  of  the  adductors,  and  ramify  about  the 
internal  condyle. 

Several  small  branches  go  off  from  the  great  artery 
soon  after  it  passes  through  the  tendon  of  the  adductors, 
which  are  distributed  to  the  contiguous  muscles.  Some  of 
them  are  also  called 

Perforating  Arteries. 

Among  them  is  the  principal  medullary  artery  of  the  os 
femoris. 

In  the  ham,  the  great  vessel  there  called 
POPLITEAL , 

generally  sends  off  several  small  branches.  Two  of  them 
go  off  on  the  inside,  one  above  and  the  other  below  the 
knee;  and  two  on  the  outside  in  the  same  manner.  They 
are  named,  from  their  situation.  The  Superior  and  Inferior 
Internal  and  The  Superior  and  Inferior  External  Articu- 
lary  Arteries. 

The  Superior  Internal  artery  perforates  the  tendon  of 
the  adductors  above  the  internal  condyle,  and  ramifies 
minutely  on  the  inner  side  of  the  joint. 

The  Superior  External  artery  passes  through  the  lower 
portion  of  the  biceps  above  the  external  condyle,  and  ra- 
mifies minutely  on  the  outer  side  of  the  joint.  Its  superior 
ramifications  anastomose  with  those  of  the  descending 
branch  of  the  external  circumflex,  while  its  inferior  rami- 
fications communicate  with  those  of  the  corresponding 
artery  below. 


296 


Arteries  of  the  Leg. 

The  two  inferior  arteries  originate  nearly  opposite  to 
the  middle  of  the  joint,  and  pass  downwards. 

The  Inferior  Internal  artery  passes  under  the  internal 
head  of  the  gastroc  nemius  muscle,  on  the  posterior  and 
internal  side  of  the  head  of  the  tibia.  Its  ramifications 
communicate  with  those  of  the  corresponding  artery  above 
and  of  the  tibialis  antica.  Below  they  also  extend  to  the 
interior  of  the  joint. 

The  Inferior  External  artery  passes  under  the  external 
head  of  the  gastroc  nemius  and  the  plantaris  muscle,  and 
continues  under  the  external  lateral,  and  the  capsular  liga- 
ment. It  is  distributed  on  the  external  and  inferior  part 
of  the  articulation,  and  sends  also  some  branches  to  the 
interior  of  the  joint. 

There  is  frequently  an  azygous  vessel,  called  the  Middle 
Articular  artery,  which  arises  from  the  back  of  the  popli- 
teal, and  is  distributed  to  the  posterior  parts  of  the  arti- 
culation. 

The  POPLITEAL  artery,  after  this,  sends  off  a few 
small  branches  to  the  heads  of  the  muscles  of  the  leg,  and 
among  them  one  of  considerable  length,  to  each  of  the 
heads  of  the  gastroc  nemii.  At  the  under  edge  of  the 
popliteus  muscle,  it  sends  off  horizontally  a large  branch 
which  passes  directly  forward  between  the  tibia  and  fibula, 
above  the  commencement  of  the  interosseous  ligament. 
After  this  it  continues  to  descend,  nearly  in  the  same  di- 
rection, under  the  soleus  muscle,  behind  the  tibia;  but 
before  it  has  proceeded  further  than  twelve  or  fifteen 
lines,  it  sends  off  a branch  which  forms  an  acute  angle 
With  it,  and  approaches  near  the  fibula,  along  which  it 
descends. 

The  branch  sent  off  anteriorly,  is  called  the  anterior 
tibi  al  artery. 


Anterior  Artery  of  the  Leg'.  297 

The  main  trunk,  which  continues  downwards,  is  called 
the  posterior  tibiae  artery; 

And  the  branch  which  descends  near  the  fibula  is  called 
the  Peroneal  or  Fibular  artery. 

The  anterior  tibiae  Artery , 

After  its  arrival  on  the  anterior  part  of  the  leg,  passes  down 
close  to  the  interosseous  ligament,  with  the  tibialis  anticus 
muscle  on  the  inside,  and  the  extensor  communis  on  the 
outside,  in  the  first  part  of  its  course;  and  afterwards,  with 
the  extensor  pollicis  pedis  on  the  outside  of  it.  It  gradually 
inclines  internally  as  it  descends,  so  that  a little  above  the 
ankle  it  is  upon  the  front  partof  the  tibia.  It  proceeds  thence 
with  the  tendons  of  the  extensor  digitorum  pedis,  under  the 
annular  ligament,  to  the  upper  surface  of  the  foot,  on  which 
it  continues  to  the  interstice  of  the  first  and  second  meta- 
tarsal bones,  where  it  descends  to  anastomose  in  the  way 
presently  to  be  mentioned. 

In  this  course  it  sends  off,  soon  after  it  has  arrived  at 
its  anterior  situation,  a recurrent  branch , which  is  distri- 
buted to  the  heads  of  the  muscles  and  the  ligaments  of  the 
articulation,  and  which  anastomoses  with  the  branches  of 
the  inferior  articular  arteries.  It  also  sends  off,  on  each 
side,  many  arterial  twigs  to  the  contiguous  muscles,  and 
very  frequently  one  branch  of  considerable  size,  which 
passes  down  near  the  fibula. 

When  it  has  arrived  near  the  end  of  the  tibia,  it  sends 
a branch  on  each  side,  called  the  Internal  and  External 
Malleolar.  On  the  top  of  the  foot,  among  several  smaller 
arteries,  it  sends  off  a branch  under  the  extensor  brevis 
digitorum  pedis,  which  passes  outwards  and  forwards, 
and  supplies  the  muscles,  &c.,  on  the  upper  part  of  the 
foot.  1 his  vessel  is  called  Arteria  Tarsea.  There  is  also 
Voi.  II.  2 P 


298  Posterior  Tibial  and  Peroneal  Arteries. 

another  branch,  called  Metatarsea , which  generally  arises 
about  the  middle  of  the  foot,  and  passes  obliquely  out- 
ward and  forward,  supplying  the  contiguous  parts. 

The  anterior  tibial  artery,  having  arrived  at  the 
space  between  the  metatarsal  bones  of  the  first  and  second 
toes,  bends  down  to  the  sole  of  the  foot,  but  previously 
sends  off  a branch  which  passes  near  the  external  edge  of 
the  metatarsal  bone  of  the  great  toe,  and  divides  into  two 
branches,  one  of  which  goes  to  the  outside  of  the  great 
toe,  and  the  other  to  the  opposite  side  of  the  toe  next  to  it. 

The  posterior  tibial  Artery , 

After  sending  off  the  anterior  tibial,  parts  with  the  Pero- 
neal or  Fibular , as  has  been  already  stated,  and  then 
continues  on  the  back  of  the  tibia,  behind  the  internal 
ankle,  to  the  sole  of  the  foot. 

The  Peroneal  or  Fibular  Artery 
Is  not  commonly  so  large  as  either  of  the  two  other 
arteries  of  the  leg,  nor  is  it  so  constant.  It  passes  down 
very  near  the  internal  edge  of  the  fibula.  It  is  in  contact, 
for  some  distance,  with  the  tibialis  posticus  muscle,  and  is 
anterior  to  the  soleus  and  the  flexor  pollicis  longus;  it 
sends  branches  to  the  contiguous  muscles.  After  it  has 
passed  along  two  thirds  of  the  length  of  the  fibula,  it 
frequently,  but  not  always,  divides  into  an  anterior  and  a 
posterior  branch. 

The  anterior  peroneal  soon  perforates  the  interosseous 
ligament,  and  passing  down  some  distance  on  its  anterior 
surface,  continues  to  the  ankle  and  upper  surface  of  the 
foot.  It  gives  ramifications  to  all  the  contiguous  parts  in 
its  progress,  and  anastomoses  with  some  of  the  small  ra- 
mifications of  the  tibialis  antica. 


299 


Arteries  of  the  Foot. 

The  posterior  peroneal  branch  is  the  continuation  of 
the  main  trunk.  It  passes  behind  the  external  malleolus, 
and  ramifies  upon  the  external  side  of  the  foot. 

The  posterior  Tibi al  artery  passes  down,  inclining 
rather  obliquely  inwards,  between  the  gastroc  nemius 
internus,  which  is  posterior  to  it,  and  the  tibialis  pos  icus 
and  flexor  digitorum,  which  are  anterior  to  it.  Upon  the 
leg  it  gives  off  many  small  branches,  one  of  which,  termed 
the  Arteria  Nutritia  Tibiae , comes  off  high  up,*  and,  after 
ramifying  as  it  descends,  sends  a branch  to  the  medullary 
foramen  of  the  tibia. 

At  the  lower  part  of  the  leg  the  posterior  tibial  is 
situated  rather  superficially  between  the  tendo  Achillis  and 
the  tibia.  It  proceeds  thence  behind  the  internal  ankle  in  a 
deep  situation,  covered  by  an  annular  ligament,  and  passes 
between  the  abductor  muscle  of  the  great  toe  and  the  bones 
of  the  tarsus.  It  then  divides  into  two  branches — the  in- 
ternal and  the  external  plantar  arteries. 

The  Internal  Plantar  Artery 

Is  commonly  much  smaller  than  the  other  ramification.  It 
passes  in  the  direction  of  the  internal  edge  of  the  foot, 
but  at  some  distance  from  it,  and  often  lies  between  the 
aponeurosis  plantaris  and  the  abductor  pollicis.  It  fre- 
quently terminates  by  anastomosing  with  one  of  the  arte- 
ries of  the  great  toe,  and  in  its  course  sends  off  several 
branches  to  the  contiguous  parts  on  each  side  of  it. 

The  External  Plantar  Artery 
Is  the  continuation  of  the  main  trunk.  It  proceeds  out- 
wards and  forwards  between  the  short  flexor  of  the  toes 


* This  artery  sometimes  comes  off  from  the  popliteal. 


300 


Arteries  of  the  Foot. 

and  the  flexor  accessorius;  and  continues  afterwards  be- 
tween the  first  of  these  muscles  and  the  abductor  of  the 
little  toe.  At  the  metatarsal  bone  of  the  little  toe  it  begins 
to  curve,  and  continues  its  curvature  across  the  other 
metatarsal  bones  to  the  interstice  between  the  great  toe 
and  the  one  next  to  it,  passing  between  the  tendons  of  the 
long  extensor  and  the  metatarsal  bones.  At  the  interstice 
above  mentioned,  it  anastomoses  with  the  tibialis  antica. 
The  curvature,  thus  formed,  is  called  the  Arcus  Plantaris. 

In  this  course,  the  External  Plantar  sends  off  several 
branches  to  the  heel  and  the  parts  of  the  foot,  especially 
on  the  external  side;  the  deep  seated  parts  of  the  foot  be- 
ing supplied  from  the  curve. 

Digital  branches  go  off  from  the  curve,  as  they  do 
in  the  hand,  from  the  curve  of  the  ulnar.  There  is  first 
a small  branch  to  the  outside  of  the  little  toe;  and  then 
three  regular  branches,  which  pass  to  the  junction  of  the 
roots  of  the  four  small  toes,  and  divide,  like  the  digital 
arteries  of  the  hand,  so  as  to  send  a branch  to  the  side 
of  each  toe.  These  digital  arteries  pass  between  the  muscle 
called  Transversalis  Pedis  and  the  metatarsal  bones.  Near 
the  heads  of  these  bones,  each  of  them  generally  sends 
off  two  arteries  that  pass  upwards  between  the  interossei 
muscles  and  the  bones,  and  anastomose  with  the  ramifica- 
tions from  the  top  of  the  foot. 

The  External  Plantar , soon  after  sending  off  the  third 
digital  artery,  anastomoses  with  the  anterior  tibial,  and 
then  continues  to  the  junction  of  the  root  of  the  great  toe 
with  the  one  next  to  it,  when  it  divides  into  two  branches, 
which  go  to  the  opposite  sides  of  those  toes.  In  its  course 
it  also  sends  a branch  to  the  internal  side  of  the  great  toe. 


L 


A TABLE 

XHIB1TING  THE  DISTRIBUTION  OF  THE  BRANCHES  OF  THE  AORTA. 


o mioxak  Arter.e' 


The  COMMON  TRUNK 
)f  the  Right  Subclavian 
Right  Common  Carotid 


The 


The  Superior  Thy, 

Tl»c  Facial 

The  Inferior  Pharyngeal 


(The  Thyroid  Gland.  Tlic  Larynt. 

{The  parte  eonliguooi  to  the  Or  II  voider. 
(The  Tongue-  Sublingual  Gland  The  Pha- 

{ I hi. 


At  the  Curvature . 


t appropriated 

the  head.  They  proceed  on  the  J 
aide  of  the  trachea,  and  dniile  v 
at  the  upper  edge  of  the  thy-  \ 
roid  cartilage,  into 


TU  rXTKHN.il.  CAROTID, 
whic  h it  principally  apprnpria.  / 
trd  IO  the  exterior  of  the  \ The  Occipital 
bead,  and  the  upper  parti  of 
the  neck.  It  give.  off 


The  Poeterior  Auricular 


The  Internal  Maaillary 
V^The  Temporal. 


itigiioua  pant. 

r poatrrior  part  of  the  Cranium  externally. 
Hie  cavity  nf  the  Tympanum. 

" tigiioua  to  the  external  Ear. 

f The  Superior  and  Inferior  Maxillary  bones 
r Pterygoid  mutclea  Die 
The  Dura  Mater  I'he  Interior  of 


r The  Superic 
J The  Fiucca 
3 Palate.  Thu 
l the  Note. 


u. 

TU  INTERNAL  C.1NOT/D.  J 
interior  of  t\ie  cranu 


and  ^ 


Ophthalmic  Artery,  to  the  Eye 
Anterior  Artery  of  ( ... 

the  Brain  ^ The  ante 

The  Middle  Artery  of  (The  middle,  and  part  of  the  poitcrioi 
tlic  Brain  £ tion  of  the  Cerebrum. 


ita  nppendagej 
portion  of  the  Cerebrum. 


i< 


w ^ 

£ i 


Between  the  Curva. 
tune  and  the  great 

Bifurcation 


TU  LIFT  SI  BCI  .lt  IAN, 


Tlic  liuofiUft.lt 

The  Mrxuoa  iuvncr 
The  Phrttif  Jrirrin 
Oi.Ll.tC  ART.  HV 
SUC EH IOH  MESENTERIC 
Cipnltr 


Each  of  the  Subclavian*  if  the  flrat  portion  of  the  great  artery  of  tilt 
Upper  Extremity  of  ita  rcapective  aide 


Th.  Intern.)  M.n.AA7'"l”70"",'lf 

C Ccrrbellum.  The  potte- 
Tbe  Vertebral  to  the  < rior  portion  of  the 
C Cerebrum. 

Tlic  Inferior  Thyroid  (Thyroid  uland.  Tra- 
to  the  { chea  (Eaophagua. 

Tlic  Superior  Inter- (Some  of  Hie  Intercotul 


The  Cervical,  to  the  < 


The  Scapular) . to  the 


f Mutclea,  Clanda,  i 
Nervea.  fcc..  on  i 
Neck. 

’ Miiaclea  of  the  Neck 
doraum  of 


f Mutclea  ol 
$U,.  on  Hi. 
C the  Scap 


TU  AXILLARY 
la  the  next  portion  o 
the  artery  of  th< 
upper  extremity  It 


\ C 

| EMU  LG  ENTS 

I IjtmbuT  . trrertr, 

....... 


To  the  Trachea  and  auhatanee  of  the  Lung*. 

To  Uic  (Eaophagua. 

To  mu#  or  l*n  uf  the  dower  intcrcnUalK’ifca. 

To  the  diaphragm 

To  thr  atoiiiacli,  liver,  and  apleen. 

A I moat  all  tlic  amall  intestine*,  and  part  of  the  great. 

Cl.mdulx  Ken  ale  a.  , 

The  Kidney*. 

The  TeetSdea.  The  Ovaries  • 

The  left  portion  of  tlur  Colon,  and  the  Reetom- 

Mutclea  on  the  loin*  and  llie  abdumco-The  apme  and  the  apinal  cavity. 
Which  i»  a pent  upon  the  Sacrum,  Coccyx,  and  Rectum. 


The  Thoracic  and  the  External  ) 
Mammary-  arteries 
To  the  Periural  and  other  mu». 


The  Scapular)  Artery, 

To  the  muaelra  about  the 
pula  and  the  poaterior  rurt  of  , 
the  thorax. 

The  Circumflex^ 

To  the  porta  about  the  upper  end  I 
of  the  Oa  Humeri. 


At  the  great  Bifurco*  / 


n.r  PRIMITIVE  ILIACSi 
One  of  a||.eh  it  divided  on  cad 
aide  of  tlic  Pelvia  into 


Tlic  INTERNAL  ILIAC, 


TU  lit*  LumLar  artery 


. StIic 

r"- 


f The  Sacrun,  internally  and  ex- 

< ten.  ally 

CThr  Cauda  Etpuna. 


C The  Blailler. 
i fhe  Uicna. 
c l he  Rettam. 


r Tlic  Muxka  on  the  upper  and 
,i, term  part  of  the  tlngb. 
ilh.  ll.pp.iM.ke. 

f The  Mu«.  a on  the  lateral  and 
5 |,i>trnr  part*  of  tlic  Oa*a  In- 


fTlie  Mutter 


n off  < The  Orp,  of  Ceneraliocr. 


TU  POPLITEAL, 


The  EXTERNAL  ILIAC, 
lie  firat  portion  of  the  great 
artery  of  the  lpwer  extremity,  ( 
which  pataca  under  Poupart  a 
ligament  to  the  thigh,  but  prv- 
vioual)  aenda  off 


V amall  artery.  »lmli  \ 

rpent  upon  i lie  iliaciit  f TU  IblOHAL  1 
inlemua,  awl  tlie  con-  I -kr*.  I 

tigiioua  portion*  of  the  I I he  *tnul  |.  irtu.nl 
abdominal  murder  and  I "f  at  artery  \ 

the  paoaa.  ' V'*  extra-  / 

\ mtlj^W.ua  at  Foil- 1 
TU  Efiijasme,  I partTh»me«t  III 
iVhieh  ia  .pent  upon  the  I •d"*"’  I 

muaclca,  and  imrgu-  I f 

menu  of  the  anterior  V 


rhe  External  Pud.c  ( Thc  t»nrd  I— r*'pn  «f  <hc 

o tlic  ex.er.or  ..art.  of  I pat  artery  lie.  on  tl.e 
the  Organ,  of  Gene-  I . l-ck  of  the  th.gl. 
rttion  /It  aenda  oil  the  articular 

' artenet,  which  anaato- 

\ mote  with  each  other, 

I and  aupply  the  contigu- 


The  Profunds 
knd  Ita  branches  thc 
two  circumflex*, 
the  muaclca  on  t 
thigh, 


A recurrent  branch  to  anaato- 
moae  with  branchc*  from 

Branche*  to  the  anterior  miu- 
clea  of  the  leg. 

Tar..!  and  m.t.ura»|  branchr. 
to  the  upper  part  of  the  foot. 


muaclca  on  the  ooUide  of 
ihe  leg. 
ie  ankle  a> 


and  the  outride  of  the 


--  •nal  and  the  external 
plantar  artrnea,  to  the  part! 
on  the  role  of  the  foot  and  the 


[To  face  pag,  3Qa] 


l A branch  to  the  thumb. 

To  the  radial  ante  of  die  index. 
^ a o the  area*  profundua. 

S To  die  murder  on  the  forearm. 
C To  Hie  wrut  and  the  hand. 


he  are i.t  r.d.limit  in  the  pahn 
of  the  hand,  which  aenda  off 
thedigjU!  arte  net  to  tlic  ride* 


301 


CHAPTER  III. 

OF  THE  PARTICULAR  DISTRIBUTION  OF  THE  VEIN'S. 

ANATOMISTS  of  great  respectability  have  very  dif- 
ferent sentiments  respecting  the  best  method  of  describing 
the  veins.  Some  of  them,  in  order  to  follow  the  course  of 
the  circulation,  commence  with  the  small  veins,  and  pro- 
ceed to  the  large  trunks  which  are  formed  by  their  union. 
Others  begin  with  the  great  veins  that  empty  into  the 
heart,  and  proceed  from  them  to  the  small  ramifications 
of  the  venous  system,  in  a direction  the  reverse  of  the 
circulation. 

As  the  last  method  is  the  easiest  for  the  student  of 
anatomy,  it  will  be  adopted  here;  but  it  must  always  be 
kept  in  mind,  that  the  blood  flows  from  the  small  veins 
into  the  larger,  and  not  from  the  latter  into  the  former,  as 
the  mode  of  description  seems  to  imply. 

The  great  trunk  of  the  venous  system  differs  consi- 
derably from  that  of  the  arterial  with  respect  to  its 
connexion  with  the  heart;  for  it  communicates  with  that 
organ  in  such  a manner  that,  when  viewed  from  before,  it 
appears  like  two  vessels;  one  opening  into  the  upper,  and 
the  other  into  the  lower  part  of  the  right  auricle.  When 
viewed  from  behind,  it  appears  like  a continued  tube, 
three  fourths  of  which  are  deficient  anteriorly;  and  to  the 
margin  of  this  deficiency  the  right  sinus  or  pouch  of  the 
heart  is  connected. 

In  some  preparations  of  the  heart,  where  all  the  great 
vessels  connected  with  it  are  much  distended  by  the  injec- 
tion, and  the  pulmonary  vessels  are  injected  first;  the  right 


302 


Veins  of  the  Heart. 

aui-ifle  is  so  much  pressed  upon  from  behind,  by  the  vessels 
which  go  to  the  right  lung,  that  the  direction  of  the  superior 
and  inferior  portions  of  the  vena  cava,  which  thus  commu- 
nicate with  it,  is  altered.  Each  of  them  is  turned  obliquely 
forwards,  so  that  it  forms  an  angle  with  the  other.  This 
occasions  them  to  appear  more  like  distinct  vessels  than 
they  otherwise  would  do. 

The  above  mentioned  portions  of  the  great  veins  are 
denominated  the  Superior  or  Descending,  and  the  Inferior 
or  Ascending  Vena  Cava ; as  if  they  were  perfectly  distinct 
and  unconnected  with  each  other. 

The  coronary  Veins, 

Which  are  exclusively  appropriated  to  the  heart,  may  be 
considered  here,  as  they  are  not  included  in  the  general 
arrangement  of  the  veins. 

The  great  vein  of  the  heart  begins  at  the  lower  part  of 
the  right  auricle,  very  near  to  the  septum,  which  divides 
the  two  auricles.  It  soon  proceeds  to  the  left,  in  a circular 
direction,  surrounded  with  adipose  matter,  in  the  deep 
groove  which  exists  between  the  left  auricle  and  the  left 
ventricle.  It  continues  between  the  auricle  and  ventricle, 
until  it  is  immediately  over  the  septum,  which  divides  the 
two  ventricles.  Here  its  direction  changes,  and  it  proceeds 
to  the  apex  of  the  heart,  where  its  small  ramifications 
anastomose  with  others  soon  to  be  described.  In  its  course 
round  the  basis  of  the  left  ventricle,  it  sends  off  several 
branches,  one  of  which  is  considerable,  that  proceed  from 
the  basis  towards  the  apex  of  the  heart,  ramifying  on  the 
surface  of  the  left  ventricle. 

A second  vein,  much  less  than  the  first,  appears  to 
proceed  from  the  great  vessel  at  its  commencement,* 


It  often  opens  into  the  auricle  by  a separate  orifice. 


Superior  Vena  Cava  and  its  Great  Branches.  303 

and  continues  on  the  lower  flat  surface  of  the  heart,  be- 
tween the  two  ventricles,  to  the  apex,  accompanied  by  a 
branch  of  the  right  coronary  artery.  This  has  been  called 
the  Middle  Vein  of  the  heart. 

In  addition  to  these  there  are  several  veins  which  begin 
at  the  right  auricle,  and  extend  on  the  surface  of  the  right 
ventricle  towards  the  apex  of  the  heart.  These  have  been 
called  the  Anterior  Veins. 

SECTION  I. 

Of  the  SUPERIOR  or  DESCENDING  VENA 
CAVA,  and  the  Veins  which  communicate  with  it. 

THIS  great  vessel  proceeds  upwards  from  the  su- 
perior and  posterior  part  of  the  right  sinus  or  pouch  of 
the  heart;*  and  a portion  of  it  is  so  involved  by  the  peri- 
cardium, that  it  seems  to  be  included  in  that  sac,  as  the 
heart  is  in  this  situation.  It  is  somewhat  anterior  as  well  as 
to  the  right  of  the  aorta.  It  continues  above  the  peri- 
cardium, adhering  to  the  right  lamina  of  the  mediastinum, 
and  rather  inclining  forward.  When  it  is  as  high  as  the 
lower  margin  of  the  upper  rib,  it  sends  off  a very  large 
branch,  which  conveys  the  venous  blood  of  the  left  arm 
and  the  left  side  of  the  head  and  neck.  This  large  vein, 
which  is  very  important,  both  on  account  of  its  size  and 
its  situation,  proceeds  in  a transverse  direction  within  the 
sternum,  almost  in  contact  with  and  but  little  below  the 
upper  and  internal  margin  of  that  bone.  Immediately  be- 
hind or  within  the  origin  of  the  leftsterno-mastoid  muscle, 
it  divides  into  the  left  subclavian,  which  preserves  a trans- 


See  the  description  of  the  heart,  in  page  52,  of  this  volume. 


304 


Vena  Azygos. 

verse  course,  and  the  left  internal  jugular,  which  proceeds 
to  the  cavity  of  the  cranium  by  the  foramen  lacerum. 

After  sending  off  this  transverse  branch  to  the  left,  the 
great  vein  continues  upwards  and  behind  the  right  sterno- 
mastoid  muscle,  and  there  sends  off,  nearly  at  right  angles, 
the  right  subclavian  vein.  After  it  has  parted  with  this 
vein,  it  takes  the  name  of  biternal  Jugular , and  continues 
to  the  right  foramen  lacerum,  in  the  basis  of  the  cranium. — 
The  superior  vena  cava  is,  therefore,  principally  formed 
by  the  union  of  the  subclavians  and  internal  jugulars  from 
each  side  of  the  body. 

Immediately  after  the  superior  cava  rises  above  the 
pericardium,  before  it  divides  as  above  stated,  it  sends  off, 
from  its  posterior  part,  a large  vein  which  is  single,  and 
therefore  called 

VENA  AZYGOS. 

This  vessel  projects  backward  above  the  right  pul- 
monary artery  and  right  branch  of  the  trachea,  and  then 
curves  downward  behind  them.  It  proceeds  down  the 
spine  to  the  right  of  the  aorta  and  at  a small  distance  from 
it,  into  the  abdomen,  between  the  crura  of  the  diaphragm, 
and  sometimes  between  some  of  the  portions  of  that 
muscle,  which  are  attached  to  the  dorsal  vertebra.  In  the 
abdomen  it  often  anastomoses  either  with  the  lumbar 
veins  or  the  vena  cava. 

The  azygos  frequently  sends  off  several  small  veins 
from  its  curvature  to  the  contiguous  parts,  and  also  the 
right  Bronchial  Vein,  which  passes  along  the  ramifications 
of  the  trachea  into  the  substance  of  the  lungs.*  In  its 
course  downwards  it  gives  off  branches  to  the  (esophagus, 
some  of  which  are  considerable. 


This  bronchial  vein  sometimes  arises  from  the  superior  cava. 


305 


Inferior  Intercostal  Feins. 

The  Inferior  Intercostal  Veins  originate  directly  or 
indirectly  from  the  azygos.  In  some  cases  there  is  no 
Superior  Intercostal  on  the  right  side;  and  then  the 
two  or  three  uppermost  of  the  right  intercostals  are  also 
derived  from  the  azygos;  and  often  originate  from  it  by 
a common  trunk,  which  soon  divides. 

Most  commonly  the  ten  inferior  intercostals  on  the 
right  side  proceed  directly  from  the  azygos,  and  accom- 
pany the  intercostal  arteries.  Their  posterior  branches 
pass  into  the  vertebral  cavity,  and  communicate  with  the 
veins  which  are  there. 

About  the  sixth  or  seventh  rib,  the  vena  azygos  fre- 
quently sends  olf  a branch  to  the  left  which  descends  on 
the  left  side  of  the  vertebrse,  and  sends  off  those  Left 
intercostal  veins  which  are  below  its  origin.  It  passes 
through  the  diaphragm  with  the  aorta,  or  to  the  left  of  it, 
and  anastomoses  either  with  the  azygos  itself,  or  in  a 
way  which  is  analogous  to  the  anastomosis  of  that  vessel. 

The  vena  azygos  may  be  regarded  as  the  great  trunk 
of  the  veins  of  the  parietes  of  the  thorax,  which  are  thus 
collected,  because  they  could  not  with  convenience  pass 
singly  to  the  vena  cava,  as  the  arteries  do  to  the  aorta. 

Soon  after  sending  off  the  vena  azygos,  the  Superior 
Cava  sends  off  the  great  transverse  branch  above  mention- 
ed. From  this  it  continues  upwards  but  a short  distance, 
when  it  divides,  behind  the  right  sterno-mastoid  muscle, 
into  the  right  subclavian  and  right  internal  jugular. 

The  branches  of  the  superior  cava,  which  thus  inter- 
vene between  the  great  trunk  and  the  subdivisions  behind 
the  sterno-mastoid  muscles,  are  often  called  the  Subclavian 
Veins;  but  they  do  not  appear  to  be  accurately  named. 
For,  1st,  they  are  not  situated  under  the  clavicle,  and, 
2dly,  they  are  the  common  trunks  of  the  subclavians  and 
internal  jugulars  united. 

Vot.  II.  2 Q 


306  Superior  Intercostal  Feins. 

There  is  a difference  in  the  places  where  some  of  the 
smaller  veins  originate  on  each  side.  The  internal  mam- 
mary and  the  inferior  thyroid,  on  the  right  side,  arise 
from  the  superior  cava,  or  from  the  subclavian  at  its 
origin.  On  the  left  side  they  arise  from  the  subclavian. 

The  superior  intercostal  Veins 
Are  somewhat  different  on  the  two  sides.  That  on  the 
right  is  often  the  smallest  and  the  least  extensive.  It 
commonly  originates  from  the  posterior  and  inferior  part 
of  the  subclavian  opposite  to  the  origin  of  the  vertebral, 
and  is  generally  distributed  to  the  first  and  second  inter- 
costal spaces,  but  rarely  to  the  third. 

The  Left  Intercostal  frequently  originates  near  the  left 
internal  mammary,  and  sometimes  in  common  with  it.  It 
descends  behind  the  aorta,  on  the  left  of  the  spine,  and 
commonly  sends  off  the  six  upper  intercostal  veins,  of 
which  the  two  or  three  superior  pass  upwards  from  a 
part  of  the  vein  which  is  opposite  to  the  third  dorsal 
vertebra.  Its  extent  is  very  different  in  different  subjects. 
In  some  instances  it  passes  so  low  as  to  supply  the  seventh 
or  eighth  intercostal  space.  This  vein  also  gives  off  the  Left 
Bronchial  Vein , which  sends  branches  to  the  oesophagus 
and  bronchial  glands. 

The  vertebral  Veins 

Arise  from  the  subclavians,  but  sometimes  they  proceed 
differently  in  different  subjects:  the  right  passing  behind, 
and  the  left  before,  the  subclavian  artery  of  its  respective 
side.  Each  of  them,  however,  becomes  contiguous  to  its 
corresponding  artery.  When  it  has  arrived  at  the  place 
in  the  transverse  processes,  where  the  artery  enters  the 
vertebral  canal,  it  sends  off  an  external  branch,  which 


Vertebral  Veins. 


30? 


passes  up,  before  and  nearly  in  contact  with,  those  pro- 
cesses. and  gives  ramifications  to  the  contiguous  muscles, 
and  also  to  the  caviti  of  the  spine.  These  last  mentioned 
ramifications  enter  by  the  lateral  apertures  between  the 
transverse  processes,  and  anastomose  with  the  veins  and 
sinuses  of  the  cavity.  The  branch  often  finally  terminates 
in  the  lateral  sinus  of  the  dura  mater,  by  passing  through 
the  foramen  near  the  mastoid  process  of  the  temporal 
bone.  The  Main  Trunk  of  the  vertebral  vein  generally 
sends  oflf  another  external  branch  to  the  muscles  near  the 
basis  of  the  neck,  and  afterwards  enters  the  canal  with 
the  vertebral  artery.  While  in  this  canal,  it  generally 
sends  off  two  branches  through  each  of  the  lateral  aper- 
tures between  the  vertebrae.  One  of  these  branches  passes 
backwards  to  the  muscles  of  the  neck;  and  the  other  pro- 
ceeds into  the  great  spinal  cavity,  and  communicates  with 
the  venous  sinuses. 

When  it  has  arrived  at  the  atlas,  the  vertebral  vein 
sends  branches  to  the  contiguous  muscles  of  the  neck.  It 
also  frequently  sends  a branch  through  the  posterior  con- 
dyloid foramen  of  the  occipital  bone  to  the  lateral  sinus. 

It  is  evident,  from  these  circumstances,  that  the  verte- 
bral vein  carries  a portion  of  blood  from  the  sinuses  of 
the  brain  and  of  the  spinal  marrow,  as  well  as  from  the 
muscles  of  the  neck,  into  the  subclavian  veins. 

The  veins  of  the  head  are  frequently  very  different  in 
different  subjects. 

The  INTERNAL  JUGULAR , 

Already  mentioned,  is  often  almost  exclusively  appro- 
priated to  the  cavity  of  the  cranium:  and  all  the  exterior 
veins  of  the  head  are  ramifications  of  one  or  more  smaller 
vessels,  which  pass  up  superficially  on  the  neck,  and  are 
denominated  External  Jugulars.  In  some  instances  almost 


308  The  Internal  Jugular. 

all  'he  exterior  veins  of  the  head  are  united  to  the  internal 
jug  a-  at  the  upper  part  of  the  neck,  and  it  of  course 
conveys  he  blood  of  the  exterior  as  well  as  of  the  interior 
parts  of  the  head.  Frequently  these  veins  are  divided 
between  the  internal  and  external  jugulars,  but  they  are 
divided  very  differently  in  different  subjects. 

Internal  Jugular,  however,  almost  always  passes 
in  the  sa  ne  direction  from  the  inside  of  the  origin  of  the 
sterno. mastoid  muscle  to  the  posterior  foramen  lacerum 
of  the  cranium.  It  is  deeply  seated  on  the  external  side  of 
the  common  carotid' artery,  and  under  the  sterno-mastoid 
muscle.  Between  the  upper  margin  of  the  thyroid  cartilage 
and  the  angle  of  the  lower  jaw,  it  often  sends  off  branches 
which  are  very  different  in  different  subjects,  but  com- 
monly pass  to  the  anterior  parts  of  the  neck  and  face: 
above  these  it  generally  sends  another  to  communicate 
with  the  external  jugular.  One  of  the  branches  which 
often  go  off  from  the  internal  jugular  is  that  which  cor- 
responds with  the  superior  thyroid  or  laryngeal  artery. 
This  vein,  which  has  sometimes  been  called  the  Guttural, 
sends  many  ramifications  to  the  thyroid  gland.  The  Rana- 
lar  veins,  which  are  so  conspicuous  under  the  tongue,  are 
also  derived  from  it;  and  it  likewise  sends  branches  to  the 
larynx  and  pharynx. 

Before  the  internal  jugular  enters  the  foramen  lacerum, 
it  suffers  a partial  dilatation,  which  is  generally  larger  on 
one  side  than  the  other.*  This  dilatation  occupies  the 
fossa  at  the  foramen  lacerum.  After  passing  through  the 

* When  the  veins  of  the  neck  are  injected  it  very  often  appears  that 
a considerable  portion  of  the  internal  jugular  is  mi'ch  larger  on  one 
side  than  the  other,  as  if  it  were  affected  with  varicose  distention. 

It  also  often  appears  that  the  general  arrangement  of  the  exterior 
vein  is  different  on  the  two  sides  of  the  head  and  neck. 


309 


The  Internal  Jugular . 

aforesaid  foramen,  the  internal  jugular  terminates  in  the 
lateral  sinuses  of  the  dura  mater.*  These  and  the  other 
sinuses  within  the  cavity  of  the  cranium  are  important  por- 
tions of  the  venous  svstem,  which  are  interposed  between 
the  smaller  branches  spread  upon  the  pia  mater  and  the 
great  trunks  of  the  neck.  They  are  described  in  the 
account  of  the  brain,  (Vol.  I.  p.  319).  Into  these  sinuses 
the  very  numerous  veins  of  the  pia  mater  open,  proceed- 
ing to  the  sinuses  in  a direction  the  reverse  of  that  in 
which  the  blood  flows  in  those  channels. 

These  veins  are  divided  very  minutely  on  the  pia  mater 
before  they  enter  the  substance  of  the  brain. 

Into  one  of  these  sinuses,  denominated  the  Cavernous , 
the  ophthalmic  vein  discharges  its  contents.  This  vein 
proceeds  from  the  anterior  part  of  the  sinus  into  the  orbit 
of  the  eye  through  the  sphenoid  fissure.f  Its  ramifications 
correspond  generally  with  those  of  the  ophthalmic  artery  ;j; 
and  some  of  them  pass  out  of  the  orbit  to  anastomose  with 
the  branches  of  the  facial  vein. 

The  superficial  veins  of  the  neck  are  variously  arranged 
in  different  persons.  There  is  often  one  considerable  vein, 

The  EXTERNAL  JUGULAR , 

Which  is  sent  off  by  the  subclavian,  very  near  its  union 
with  the  internal  jugular;  but  sometimes  it  goes  off  from 

* It  is  asserted  that  the  internal  coat,  or  lining  membrane  of  the 
internal  jugulars,  is  continued  into  the  lateral  sinuses,  and  extends 
throughout  all  the  sinuses  of  the  dura  mater;  so  that  the  blood,  during 
its  passage  through  the  sinuses,  does  not  come  in  contact  with  any 
membrane  different  from  that  of  the  veins. 

f See  the  account  of  this  fissure  in  Vol.  I.  p.  56. 
t The  Vasa  Vorticosa  of  the  choroides  are  one  of  the  exceptions  to 
this.  See  Vol.  I . p.  354. 


310  The  External  Jugular. 

that  vein  much  nearer  the  shoulder.  There  are  sometimes 
two  external  jugulars,  an  anterior  and  a posterior,  nearly 
of  equal  size.  More  frequently  one  of  them  is  much  smaller 
than  the  other.  In  a majority  of  cases,  the  principal  ex- 
ternal jugular  goes  off  near  the  junction  of  the  internal 
jugular  and  subclavian,  as  above  stated,  and  proceeds 
upwards  towards  the  angle  of  the  lower  jaw,  passing 
between  the  platysma  myoides  and  the  sterno-mastoid 
muscle.  It  often  sends  off,  at  the  basis  of  the  neck,  one  or 
more  branches  to  the  contiguous  muscles,  and  then  pro- 
ceeds upwards.  Near  the  angle  of  the  jaw,  it  often  com- 
municates with  the  internal  jugular:  it  then  continues 
upwards,  covered  with  the  parotid  gland,  near  the  tem- 
poral artery,  and  finally  divides  into  superficial  and  deep- 
seated  temporal  branches. 

The  External  Jugular , near  the  angle  of  the  jaw,  often 
sends  off  the  facial  vein,  which  crosses  the  basis  of  the 
lower  jaw,  near  the  facial  artery,  and  distributes  branches 
to  the  side  of  the  face  and  to  the  forehead.  It  also  very 
often  sends  off,  near  this  place,  the  internal  maxillary 
vein,  which  generally  ramifies  in  such  a manner  that  its 
branches  correspond  with  those  of  the  internal  maxillary 
artery.  Veins  which  correspond  to  some  of  the  other 
branches  of  the  external  carotid  artery,  the  lingual,  occi- 
pital, &c.,  are  often  sent  off  near  this  place  by  the  external 
jugular.  They  take  the  names  of  the  arteries  to  which 
they  correspond,  and  commonly  accompany  them. 

The  SUBCLAVIAN-  Vein , 

Although  it  originates  differently  on  the  two  sides  of 
the  neck,  is  situated  alike  on  each  of  them.  After  parting 
with  the  internal  jugular,  it  proceeds  over  the  first  rib, 
under  the  clavicle,  and  does  not  pass  between  the  scaleni 


General  Account  of  the  Great  Vein  of  the  Arm . 311 

muscles,  as  is  the  case  wi  h the  arteries,  but  before  the 
anterior  muscle.  It  soon  joins  the  great  artery  of  the  arm, 
and  proceeds  before  or  below  it  to  the  axilla.  In  this 
situation  it  gives  off  branches  to  the  contiguous  parts, 
which  correspond  with  those  given  off  by  the  artery.  In 
this  course  it  also  often  gives  off  a large  branch,  called  the 

CEPHALIC, 

Which  soon  becomes  superficial,  and  proceeds  down- 
wards  between  the  margins  of  the  deltoid  and  pectoral 
muscles:  it  continues  superficial  on  the  external  side  of  the 
biceps  muscle,  sending  off  many  subcutaneous  branches* 
Near  the  external  condyle  of  the  os  humeri,  it  generally 
sends  off  a branch  towards  the  middle  of  the  anterior 
part  of  the  fore  arm,  which  is  called  the  Median  Cephalic , 
and  also  some  other  superficial  branches.  It  then  continues 
over  the  radius,  and  inclining  to  the  back  of  the  fore  arm, 
until  it  arrives  at  the  back  of  the  hand,  where  it  divides 
into  branches,  some  of  which  go  to  the  thumb. 

In  the  axilla,  the  great  vein,  there  called 

The  AXILLARY  Vein , 

Generally  divides  into  two  or  three  branches.  One,  which 
is  commonly  the  largest,  and  appears  like  the  continuation 
of  the  main  trunk,  is  called 

The  basilic  Vein. 

This  vessel  passes  down,  deeply  seated,  to  the  bend  of  the 
elbow.  It  becomes  superficial  near  the  internal  condyle, 
and  divides  into  several  branches.  One  of  these  generally 
proceeds  to  join  the  median  branch  of  the  cephalic,  and 
from  the  union  of  the  two  branches  is  formed  the  median 
vein,  which  passes  down  near  the  middle  of  the  anterior 


312  General  Account  of  the  Great  Vein  of  the  Arm. 

part  of  the  fore  arm.  This  vein  generally  sends  off  a 
branch  which  proceeds  internally,  and  anastomoses  with 
the  deepseated  veins  of  the  forearm. 

There  are  frequently  two  other  branches  of  the  basilic 
vein.  One,  which  is  small,  passes  down  on  the  ulnar  side 
of  the . anterior  part  of  the  forearm,  but  does  not  extend 
to  the  wrist.  The  other  passes  down  on  the  ulna,  and 
gradually  proceeds  to  the  back  of  the  hand,  when  it 
divides  into  several  branches,  one  of  which  is  generally 
appropriated  to  the  little  finger. 

The  AXILLART  vein,  after  the  basilic  leaves  it, 
sometimes  divides  into  two  branches,  and  sometimes 
continues  undivided.  In  either  case  it  accompanies  the 
humeral  artery,  and  takes  the  name  of  HUMERAL 
Vein  or  Veins.  It  sends  off  branches  which  correspond 
to  those  of  the  artery,  and  continues  to  the  bend  of  the 
elbow:  here  it  is  so  divided,  that  two  of  its  ramifications 
accompany  each  of  the  three  arteries  of  the  fore  arm. 
These  ramifications  sometimes  communicate  with  each 
other  by  anastomosing  branches  near  the  elbow,  and  they 
communicate  also  with  the  superficial  veins. 

The  superficial  veins  of  the  arm  are  so  different  in  dif- 
ferent subjects,  that  a general  description  will  rarely 
apply  accurately  to  an  individual  case.  It  may,  however, 
be  observed,  that  a Cephalic  vein  will  generally  be 
found,  which  very  frequently  arises  from  the  subclavian 
instead  of  the  axillary,  and  commonly  continues  to  the 
hand  on  the  radial  side  of  the  arm.  The  superficial 
veins,  on  the  ulnar  side  of  the  forearm,  very  frequently 
are  branches  of  a large  vein  which  accompanies  the 
humeral  artery  to  the  elbow,  viz.,  the  basilic;  but  the 
median  vein,  formed  by  branches  of  the  cephalic  and 
basilic  veins,  is  very  often  not  to  be  found. 


Situation  of  the  Inferior  Vena  Cava. 


313 


SECTION  II. 

Of  the  INFERIOR  VENA  CAVA,  and  the  Veins 
which  are  connected  with  it. 

THIS  great  vessel  exceeds  the  Superior  Cava  in 
diameter.  It  proceeds  from  the  lower  part  of  the  right 
auricle,  and  very  soon  perforates  the  diaphragm,  at  a 
small  distance  in  front  of  the  spine,  and  rather  to  the 
right  of  the  center.  As  the  pericardium  adheres  to  the 
diaphragm  at  this  place,  the  vessel  appears  to  leave  it 
abruptly.  Immediately  after  leaving  the  diaphragm,  it 
proceeds  along  a groove  in  the  posterior  edge  of  the 
liver,  formed  bv  the  great  lobe  and  the  lobulus  Spigelii.* 
After  leaving  the  liver,  it  continues  downwards,  inclining 
backward  and  to  the  left,  and  is  soon  in  contact  with  the 
aorta,  which  is  on  the  left  of  it.  It  accompanies  the  aorta 
to  its  great  bifurcation,  and  divides  in  the  same  manner.  It 
sends  off,  during  this  course,  branches  to  the  Diaphragm, 
Liver,  Right  Renal  Gland,  the  Kidneys,  and  the  Testicles; 
and  also  the  Lumbar  and  Middle  Sacral  veins. 

The  Inferior  Phrenic  Veins 

Are  thus  denominated  to  distinguish  them  from  other 
veins,  which  are  derived  from  the  internal  mammarv,  Stc. 
They  generally  accompany  the  phrenic  arteries,  and  are 
distributed  in  the  same  manner. 

* Sometimes  it  is  completely  surrounded  by  the  liver. 

Vol.  II.  2 R 


31-4  • Vena  Portcc  V entrails. 

The  HEPATIC  Veins 

Pass  off  from  the  vena  cava,  nearly  at  right  angles,  into 
the  substance  of  the  liver,  while  it  is  in  the  groove  of 
that  viscus,  and  before  it  has  proceeded  more  than  eight 
or  ten  lines  from  the  heart. 

They  arise  from  the  anterior  part  of  the  vena  cava,  and 
are  generally  three  in  number.  Sometimes  there  are  two 
only,  but  then  one  of  them  divides  immediately  after  it 
enters  the  substance  of  the  gland. 

The  distribution  of  these  vessels  in  the  liver  has  been 
detailed  in  the  account  of  that  organ,  and,  therefore,  need 
not  be  stated  here;  but  the  veins  which  unite  to  form  the 
vena  portarum,  and  the  trunk  of  that  great  vein  also,  be- 
fore it  is  connected  with  the  liver,  may  be  regarded  as  a 
portion  of  the  regular  venous  system,  and  ought  now  to 
be  considered. 

The  VENA  PORTARUM 
Passes  downwards  from  the  great  sinuB  of  the  liver  behind 
the  pancreas,  and  inclining  to  the  left.  In  this  course  it 
sends  branches  to  the  gall  bladder,  the  stomach  and  pylo- 
rus, and  the  duodenum.  At  the  upper  and  posterior  edge 
of  the  pancreas,  it  sends  off  a very  large  branch  to  the 
spleen,  which  often  passes,  with  slight  meanders,  along  a 
groove  in  the  pancreas. 

The  SPLENIC  Vein 

Often  sends  off  the  inferior  mesenteric  vein,  which 
proceeds  downwards  between  the  aorta  and  the  left  por- 
tion of  the  colon.  It  also  sends  off  some  of  the  coronary 
veins  and  the  left  gastro  epiploic  vein  to  the  stomach; 
many  small  branches  to  the  pancreas;  and,  finally,  either 


Superior  Mesenteric  and  Emulgent  Veins , 315 

from  the  main  trunk  or  its  branches  before  thev  enter  the 
spleen,  the  venae  breves,  which  pass  to  the  great  extremity 
of  the  stomach.  Before  it  enters  the  spleen,  it  forms 
several  ramifications,  which  accompany  the  branches  of 
the  splenic  artery. 

After  sending  off  the  splenic,  the  Vena  Porlarum  takes 
the  name  of 

The  SUPERIOR  MESENTERIC  Vein ; 

Which  is  larger  than  the  splenic,  and  passes  from  behind 
the  pancreas,  before  the  transverse  portion  of  the  duodenum, 
into  the  mesentery;  where  it  accompanies  the  superior 
mesenteric  artery. 

It  is  evident  that  the  above  described  portion  of  the 
vena  portarum  simply  performs  the  functions  of  a great 
vein;  but  when  it  takes  on  the  arrangements  for  entering 
the  liver,  it  no  longer  acts  like  a vein,  but  an  artery. 

The  lower  portion  of  the  trunk  of  this  vein  and  its 
ramifications  is  denominated  Vena  Portae  Ventralis.  The 
part  which  ramifies  in  the  liver,  Vena  Portae  Hepatica. 

The  Capsular  Veins 

Are  small  vessels,  one  on  each  side.  That  on  the  right 
passes  from  the  vena  cava  to  the  right  glandula  renalis. 
That  on  the  left  arises  from  the  left  emulgent  vein. 

The  EMULGENT,  <jr  RENAL,  Veins 
Are  very  large  vessels;  and,  like  the  arteries,  go  off  nearly 
at  right  angles,  one  to  each  kidney. 

The  right  emulgent  vein  is  not  so  long  as  the  left,  and 
it  is  rather  anterior  to  its  corresponding  artery.  The  left 
emulgent,  in  its  course  to  the  kidney,  crosses  the  aorta, 
and  is  anterior  to  it. 


316  Small  Branches  of  the  Cava.  Iliac  Veins. 

These  veins  pass  to  the  sinus  of  each  kidney,  and 
ramify  before  they  enter  it.  The  ramifications  follow 
those  of  the  arteries. 

The  Spermatic  Veins 

Arise  one  on  each  side:  the  right  from  the  vena  cava,  and 
the  left  from  the  emulgent  vein.  They  proceed  downwards 
behind  the  peritoneum,  and  on  the  psoas  muscle  generally 
divide  into  many  branches,  which  communicate  with  each 
other  as  they  progress  downwards,  and  form  a plexus  de- 
nominated Corpus  Pampiniforme.  These  branches  proceed 
in  the  spermatic  cord  to  the  back  of  the  testis.  The  prin- 
cipal part  enters  the  body  of  that  gland;  but  some  of  the 
branches  go  to  the  epididymis.  In  females  the  spermatic 
vein,  like  the  artery,  passes  to  the  ovary,  the  uterus  and 
its  appendages,  &c. 

The  Lumbar  Veins 

Correspond  to  the  arteries  of  the  same  name.  They  arise 
from  the  posterior  and  lateral  parts  of  the  inferior  cava, 
and  those  on  the  left  side  pass  under  the  aorta. 

The  Middle  Sacral  Vein 

Resembles  the  artery  of  the  same  name  in  its  origin  and 
distribution. 

The  INFERIOR  VENA  CAVA  accompanies  the  aorta 
to  the  space  between  the  fourth  and  fifth  lumbar  vertebrae, 
and  there  it  also  divides  into  the  two 

PRIMITIVE  ILIAC  VEINS. 

The  left  vein  crosses  behind  the  artery  of  the  right 
side,  and  rather  behind  the  left  primitive  iliac  artery, 
which  it  accompanies  until  they  are  opposite  to  the  junc- 


Internal  Iliac  and  its  Ramifications.  317 

tion  of  the  sacrum  and  ilium,  when  it  divides  again,  like 
the  artery,  into  the  internal  and  external  iliac  veins. 

The  INTERNAL  ILIAC  or  HYPOGASTRIC  Vein 
Descends  into  the  pelvis  behind  the  artery,  which  it  ac- 
companies. Its  ramifications  correspond  in  general  with 
those  of  the  artery,  and,  therefore,  need  not  be  particu- 
larly described. 

The  venjE  vesicales 

Have  such  peculiarities  that  their  ramifications  require 
particular  attention.  They  arise  from  the  hypogastric, 
very  near  the  origin  of  the  obturator,  and  are  large  as 
well  as  numerous. 

They  are  somewhat  different  in  the  two  sexes.  In  men 
they  form  a remarkable  plexus  on  the  lateral  and  inferior 
portions  of  the  bladder,  and  on  the  vesiculse  seminales. 
This  plexus  extends  more  or  less  to  the  prostate:  from  it 
a number  of  veins  proceed  to  the  symphysis  of  the  os 
pubis,  which  communicate  in  their  course  with  the  pudic 
vein.  From  thence  arises  the  great  vein  of  the  penis, 
which  proceeds  in  the  groove  between  the  corpora  caver- 
nosa, and  terminates  in  the  glans  penis.  This  vein  often 
divides,  near  the  root  of  the  penis,  into  two:  one  of  which 
is  in  the  groove,  and  the  other  more  superficial.* 

In  females,  the  venae  vesicales  form  a considerable 
plexus  on  each  side  of  the  bladder  and  vagina.  Many 
veins  pass  from  these  to  the  upper  portions  of  the  bladder 
and  the  contiguous  parts,  and  form  plexuses.  The  clitoris 

* The  pudic  veins  accompany  the  arteries  of  that  name.  They  com- 
municate with  the  plexus,  as  above  mentioned,  and  continue  into  the 
penis. 


I 


318  Ramifications  of  the  External  Mac. 

has  a dorsal  vein  like  the  penis,  and  it  originates  in  sr 
manner  analogous  to  the  dorsal  vein  of  the  male. 

The  EXTERNAL  ILIAC  Vein. 

The  great  trunk  of  the  veins  of  the  lower  extremity  pro- 
ceeds on  the  inside  of  the  artery,  under  the  crural  arch  or 
Poupart’s  ligament.  Before  it  passes  from  under  the  arch, 
it  sends  off  two  branches  which  answer  to  the  circumflex 
artery  of  the  ilium  and  to  the  epigastric  artery. 

The  Circumflex  Vein 

Arises  from  the  external  side  of  the  iliac  vein,  and  passes 
towards  the  anterior  end  of  the  spine  of  the  ilium.  It 
divides  into  branches  which  accompany  those  of  the  artery 
of  the  same  name. 

The  Epigastric  Vein 

Arises  from  the  external  iliac,  and  accompanies  the  epi- 
gastric artery. — After  passing  a small  distance  inward 
and  downward,  it  turns  up  on  the  inside  of  the  abdominal 
muscles.  In  the  first  part  of  its  course  it  sends  off  some 
small  branches  to  the  spermatic  cord. 

After  passing  beyond  Poupart’s  ligament,  the  name  of 
the  great  vessel  is  changed  from  external  iliac  to 

FEMORAL  VEIN. 

It  proceeds  downwards  at  first  on  the  inside  of  the  femo- 
ral artery,  but  gradually  changes  its  relative  situation,  so 
that  in  the  thigh  and  in  the  ham  it  is  behind  or  on  the 
outside  of  that  vessel. 

At  a short  distance  below  Poupart’s  ligament,  after 
giving  off  some  small  branches  to  the  external  organs  of 
generation,  and  to  the  glands  of  the  groin,  it  sends  off  on 


Veins  of  the  Leg,  3X9 

the  internal  side  of  the  thigh  a very  large  vein  which 
is  called  the 

SAPHENA  MAJOR. 

This  vein  immediately  becomes  superficial,  and  passes 
down  on  the  internal  side  of  the  thigh,  somewhat  ante- 
riorly; giving  off  some  small  branches  to  the  contiguous 
parts,  soon  after  it  originates;  and  many  superficial  veins 
afterwards.  It  continues  along  the  inside  of  the  knee  and 
leg  to  the  internal  ankle,  the  anterior  part  of  which  it 
passes  over.  It  then  proceeds  along  the  internal  part  of 
the  upper  surface  of  the  foot  to  the  middle,  when  it  curves 
towards  the  external  edge,  and  joins  the  lesser  saphena. 
On  the  leg  and  foot  it  also  sends  off  many  branches,  which 
anastomose  with  each  other,  and  with  those  of  the  afore- 
said vein. 

The  femoral  vein,  after  parting  with  the  saphena, 
soon  sends  off  the  vena  profunda,  and  the  circumflexse 
also,  when  they  do  not  arise  from  the  profunda.  These 
veins  are  generally  larger  than  the  arteries  to  which  they 
correspond,  and  their  branches  are  more  numerous;  but 
they  observe  the  same  course. 

The  great  vein  accompanies  the  artery  down  the  thigh 
and  through  the  perforation  in  the  biceps;  but  it  changes 
its  relative  position,  so  that  it  is  placed  behind  or  on  the 
exterior  side  of  the  artery  at  the  lower  part  of  the  thigh. 
It  is  very  often  behind  it  in  the  ham,  where,  like  the 
artery,  it  takes  the  name  of  POPLITEAL.  In  the  ham  it 
sends  off  another  superficial  vein,  which  seems  very  ana- 
legous  to  the  basilar  vein  of  the  arm.  This  is  called 

The  Lesser  or  External  Saphena. 

It  proceeds  from  the  ham  over  the  external  head  of  the 


320  Instances  of  peculiar  arrangement  of  the  Veins * 

gastroc  nemius,  and  down  the  outside  of  the  leg,  sending- 
off  many  branches  in  its  course.  It  passes  behind  the  ex- 
ternal ankle  and  near  the  exterior  edge  of  the  upper 
surface  of  the  foot,  about  the  middle  of  which  it  inclines 
towards  the  great  saphena,  and  forms  with  it  the  anasto- 
mosis already  mentioned. 

The  popliteal  vein,  after  passing  across  the  articulation, 
ramifies  like  the  artery,  but  it  sends  two  veins,  which  ac- 
company each  of  the  three  arteries  of  the  leg. 


In  a few  instances  some  of  the  larger  veins  have  beeh 
found  to  be  arranged  in  a manner  very  different  from 
that  which  is  commonly  observed. 

One  case  of  this  kind  has  already  been  mentioned 
in  the  account  of  the  liver,*  where  the  Vena  Portarum 
terminated  in  the  Vena  Cava , below  the  liver,  without 
entering  into  it. 

Another  very  remarkable  instance  of  peculiar  arrange- 
ment is  to  be  seen  in  a preparation  now  in  the  University 
of  Pennsylvania,  in  which  the  Inferior  Cava , instead  of 
opening  into  the  lower  part  of  the  right  auricle,  passes 
behind  it,  in  the  tract  of  the  Vena  Azygos , and  opens  into 
the  Superior  Cava , in  the  place  where  the  Vena  Azygos 
usually  communicates  with  that  vessel,  receiving  the  In- 
tercostal Veins  in  its  course. 

In  this  preparation,  the  Hepatic  Veins  communicate 
directly  with  the  right  auricle,  at  its  lower  part;  the 
middle  and  left  hepatic  veins  forming  one  trunk  before 
they  enter,  and  the  right  vein  passing  in  singly. 


Sfee  note  to  p.  140,  of  this  volume. 


Pulmonary  Vessels. 


321 


Of  the  PULMONARY  Artety  and  Veins. 

Those  portions  of  the  pulmonary  artery  and  veins 
which  are  distinct  from  the  lungs  may  be  described  very 
briefly. 

It  has  been  already  observed,*  that  the  pulmonary 
artery  arises  from  the  left  and  most  anterior  part  of  the 
basis  of  the  right  ventricle,  and  proceeds  thence  obliquely 
backwards,  inclining  gradually  to  the  left  side  for  about 
eighteen  or  twenty  lines,  when  it  divides  into  two  branches, 
which  pass  to  the  two  lungs.  This  course  places  it  under 
the  curve  of  the  aorta:  for  that  great  vessel  passes  over 
the  right  branch  of  the  pulmonary  artery,  and  the  right 
side  of  the  main  trunk  of  it,  in  such  a manner  that  it  pro- 
ceeds downwards  between  the  two  branches,  and  behind 
the  angle  formed  by  their  bifurcation.  From  this  place  of 
bifurcation  a short  ligament  proceeds  to  the  lower  part  of 
the  curve  of  the  aorta,  which  is  almost  in  contact  with  it. 
This  ligament  was  originally  the  canal  that  formed  the 
communication  between  the  pulmonary  artery  and  the 
aorta  of  the  fetus. f Each  of  the  great  branches  of  the 
pulmonary  artery  takes  a direction  backwards,  and  to  its 
respective  side.  It  soon  joins  the  corresponding  branch 
of  the  trachea  and  the  two  pulmonary  veins,  being  anterior 
to  the  branch  of  the  trachea,  and  above  the  pulmonary 
veins.  It  is  also  invested,  in  common  with  them,  by  that 
portion  of  the  pleura  which  forms  the  mediastinum,  and 
thus  enters  into  the  composition  of  the  root  of  the  lungs. 

The  pulmonary  veins  are  four  in  number — two  on 
each  side.  In  conformity  to  the  mode  of  description  which 

* See  page  60  of  this  volume. 

Vol.  II.  2 S 


+ See  Page  70 


322  Pulmonary  Vessels. 

we  have  adopted,  it  may  be  said  that  they  arise  from  the 
sides  of  the  Left  Auricle , and  proceed  nearly  in  a trans- 
verse direction,  two  of  them  to  each  lung;  where  they 
accompany  the  branches  of  the  artery  and  of  the  trachea, 
being  invested  by  the  mediastinum  in  common  with  these 
branches.  It  has  been  observed,  that  they  differ  from 
veins  in  general,  by  preserving  a diameter  nearly  similar 
to  that  of  the  arteries  which  they  accompany. 


SYSTEM  OF  ANATOMY. 


PART  X. 

OF  THE  NERVES. 

The  nerves  are  those  whitish  cords  which  pass  from 
the  brain  and  spinal  marrow  to  the  various  parts  of  the 
body. 

A general  account  of  their  origin  is  contained  in  the 
description  of  the  basis  of  the  brain  and  of  the  spinal 
marrow,*  which  may  be  considered  as  introductory  to 
the  present  subject. 

The  nerves,  in  general,  appear  to  be  bundles  or  fasciculi 
of  small  cords,  each  of  which  is  composed  of  a series  of 
fibres  that  are  still  smaller.  These  fibres  consist  of  me- 
dullary matter,  which  is  derived  from  the  brain  and 
spinal  marrow,  and  is  inclosed  in  a membranous  sheath 
that  appears  to  arise  from  the  pia  mater.  The  smaller  the 
fibre,  the  more  delicate  is  the  membrane  which  invests  it. 

As  the  nerves  proceed  from  the  brain  and  spinal  mar- 
row, through  the  foramina  of  the  cranium  and  the  spine, 
they  are  inclosed  in  a sheath  formed  by  the  dura  mater; 
but  when  they  arrive  at  the  exterior  extremity  of  the 
foramina  in  those  bones,  this  coat,  derived  from  the  dura 


See  Volume  I.  page  333. 


324  General  Structure  of  the  Nerves. 

mater,  appears  to  separate  into  two  laminae.  The  exterior 
lamina  combines  with  the  periosteum,  and  the  interior 
continues  to  invest  the  nerve,  but  seems  to  change  im- 
mediately into  cellular  substance;  so  that  the  exterior 
coat  of  the  nerves  may  be  regarded  as  composed  of  cellu- 
lar membrane,  which  is  continued  from  the  sheath  derived 
from  the  dura  mater. 

It  has  been  supposed  that  the  membrane  which  forms 
the  sheaths  for  the  medullary  fibrils,  of  which  the  nerves 
are  composed,  is  of  a peculiar  nature;  but  it  appears  to  be 
derived  from  the  pia  mater,  investing  the  brain  and  the 
spinal  marrow.  It  is  very  vascular.* 

The  ramification  of  a nerve  is  simply  the  separation  of 
some  fibres  from  the  general  fasciculus.  The  branch  com- 
monly forms  an  acute  angle  with  the  main  trunk. 

The  course  of  these  branches,  from  their  origin  to  their 
termination,  is  generally  as  straight  as  possible. 

When  the  nervous  cords  are  examined  in  an  animal 
recently  dead,  there  is  an  appearance  of  white  lines  ar- 
ranged in  a transverse  or  spiral  direction.  The  cause  of 
this  appearance  is  not  well  understood. 

In  various  parts  of  the  body  networks  are  formed  by 
the  combination  of  different  nerves,  or  the  branches  of 
nerves.  In  those  instances  the  branches  of  one  nerve  unite 
with  those  of  another,  and  form  new  branches.  These 
new  branches  again  divide,  and  their  ramifications  unite 

* Several  authors  have  written  professedly  on  the  structure  of  the 
nerves,  viz.  Monro,  in  his  “ Observations  on  the  Structure  and  Func- 
tions of  the  Nervous  System.” — Bichat,  “ Anatomie  Generale.” — .Fon- 
tana, “ Treatise  on  the  Poison  of  the  Viper.” — Reil,  “ Exercitationes 
Anatomies.” — Scarpa,  “ Annotationes  Academics.” — Prochaska,  “ De 
Structura  Nervorum.” 

I regret  that  it  has  not  been  in  my  power  to  procure  Reil,  Prochaska, 

or  Scarpa. 


Plexuses. — Ganglions.  325 

with  other  new  ramifications  to  form  other  new  trunks. 
These  new  trunks  divide  again,  and  form  new  combina- 
tions in  the  same  way. 

The  trunks  last  formed  proceed  to  the  different  parts  of 
the  body,  as  other  nerves  do  which  arise  immediately 
from  the  brain. 

These  combinations  are  denominated  Plexuses.  There 
are  several  of  them  in  the  cavities  of  the  abdomen  and 
thorax,  formed  by  the  ramifications  of  the  par  vagum  and 
the  sympathetic  nerves.  The  four  lower  cervical  and  the 
first  dorsal  nerve  form  a very  remarkable  plexus  of  this 
kind,  which  extends  from  the  side  of  the  neck  to  the 
axilla,  and  forms  the  nerves  of  the  arm.  The  lumbar 
nerves  form  a similar  plexus,  although  not  so  complex, 
from  which  the  crural  nerve  arises.  The  anterior  nerves 
of  the  sacrum  also  unite  for  the  formation  of  the  great 
sciatic  nerve. 

It  appeals  to  be  clearly  ascertained,  that  the  great 
object  of  this  peculiar  arrangement  is  the  combination 
of  nervous  fibres  from  many  different  sources,  in  each  of 
the  nerves,  which  are  distributed  to  any  organ.  Thus,  the 
smaller  nerves  of  the  arm  that  are  distributed  to  the 
different  parts,  are  not  to  be  regarded  simply  as  branches 
of  any  one  of  the  five  nerves  which  are  appropriated  to 
the  upper  extremity,  but  as  composed  of  fibres  which  are 
derived  from  each  of  them. 

Many  of  the  nerves  are  enlarged  in  particular  places, 
so  as  to  form  small  circumscribed  tumours,  which  are 
denominated  Ganglions. 

These  Ganglions  are  generally  of  a reddish  colour.  By 
very  dextrousmanagement,  they  can  be  shown  to  consist 
of  a texture  of  fibres.  The  larger  cords,  which  compose 
the  nerve,  seem  suddenly  to  be  resolved  into  the  small 


326 


Structure  of  Ganglions. 

fibres,  of  which  they  consist.  These  small  fibres,  after 
proceeding  separately  a greater  or  lesser  distance,  accord- 
ing to  the  size  of  the  ganglion,  and  changing  their  relative 
situation,  are  again  combined  in  cords  which  recompose 
the  nerve. 

These  fibres  appear  to  be  surrounded  by  fine  cellular 
substance,  which  is  vascular,  moist  and  soft.  It  is  assert- 
ed that,  in  fat  subjects,  an  oily  substance,  resembling  fat; 
and  in  hydropic  subjects,  a serous  fluid  has  been  found  in 
this  texture. 

Ganglions  are  often  connected  with  but  one  nerve, 
which  seems  to  enter  at  one  extremity  and  go  out  at 
the  other.  But  they  frequently  receive  additional  branches 
from  other  nerves,  and  send  off  additional  branches  to 
parts  different  from  those  to  which  their  principal  nerves 
are  directed.  When  connected  with  but  one  nerve,  they 
have  been  called  simple  ganglions:  when  they  receive  and 
give  off  additional  branches,  they  are  denominated  com- 
pound ganglions. — It  does  not  appear  that  there  is  any 
important  difference  in  their  structure  in  these  cases. 

The  simple  ganglions  occur  in  the  nerves  of  the  spinal 
marrow — the  posterior  fasciculus  of  the  nerves  having 
always  formed  a ganglion  before  it  is  joined  by  the  anterior 
fasciculus.  The  sympathetic  nerve,  throughout  its  whole 
extent,  forms  compound  ganglions. 

The  use  of  this  particular  structure  does  not  appear  to 
be  perfectly  known.  It  seems,  however,  certain,  that  the 
different  fibres — (of  which  the  nerves  forming  ganglions 
are  composed) — are  blended  together  and  arranged  in  a 
manner  different  from  that  in  which  they  were  arranged 
before  the  nerve  entered  the  ganglion. 

It  ought  to  be  observed,  that  the  combination  of  nervous 
fibrillse,  so  as  to  bring  together  those  fibrils  which  originally 


327 


Reproduction  of  Nerves. 

belonged  to  different  cords,  seems  to  have  be6n  kept  in 
view  throughout  the  whole  arrangement  of  the  nervous 
system.  It  is  not  only  in  the  plexus  and  the  ganglion  that 
this  appears,  but  also  in  some  of  the  larger  nerves;  for  in 
them,  the  fibres  which  form  the  cords  that  compose  the 
nerve,  instead  of  running  parallel  to  each  other,  along  the 
whole  extent  of  the  nerve,  form  a species  of  plexus  in  their 
course;  separating  from  the  fibres  with  which  they  were 
originally  combined,  and  uniting  with  the  fibres  of  othef 
cords;  as  in  other  cases  of  plexus.* 

There  have  been  doubts  respecting  the  possibility  of  a 
reproduction  of  the  substance  of  the  nerves  when  it  has 
been  destroyed;  but  it  appears  to  have  been  clearly  proved 
by  the  experiments  of  Mr.  Haighton,  that  a reproduction 
does  really  take  place.f 

Nine  pair  of  nerves  proceed  from  the  brain  through 
the  foramina  of  the  cranium.  They  are  called  Nerves  of 
the  Brain , or  Cerebral  Nerves.  One  pair  pass  off  between 
the  cranium  and  the  spine,  which  are  called  Sub-Occipital. 
Twenty-nine  or  thirty  pair  pass  through  the  foramina  of 
the  spine:  they  are  denominated  Cervical , Dorsal , Lumbar 
and  Sacral , from  the  bones  with  which  they  are  respec- 
tively connected.  There  are  seven  pair  of  Cervical  nerves, 
twelve  Dorsal,  five  Lumbar,  and  five  or  six  Sacral- 
amounting,  with  the  nerves  of  the  brain,  to  thirty-nine  or 
forty  pair. 

* See  Monro’s  Observations  on  the  Structure  and  Functions  of  the 
Nervous  System.  Plate  xviii. 

t See  London  Philosophic  al  Transactions,  for  1795,  Part  1, 


328 


Olfactory  Nerves. 


NERVES  OF  THE  BRAIN. 

The  nerves  which  go  off  from  the  brain  and  medulla 
oblongata  are  named  numerically,  according  to  the  order- 
in  which  they  occur;  beginning  with  the  anterior.  They 
also  have  other  names,  which  generally  are  expressive 
of  the  functions  of  the  different  parts  to  which  they  are 
distributed. 

Those  which  go  to  the  nose  are  anterior  to  all  the  others, 
and  are  therefore  denominated 

THE  FIRST  PAIR,  OR  THE  OLFACTORY  NERVES. 

They  arise  by  three  delicate  white  fibres  from  the  under 
and  posterior  part  of  the  anterior  lobes  of  the  brain,  being 
derived  from  the  Corpora  Striata.  They  proceed  forward 
to  the  depression  on  the  cribriform  plate  of  the  ethmoid 
bone,  on  each  side  of  the  crista  galli.  The  upper  surface 
occupies  a small  sulcus  formed  by  the  convolutions  of 
the  lower  surface  of  the  brain,  and,  therefore,  has  a lon- 
gitudinal ridge  on  it.  The  lower  surface  is  flat.  Their 
texture  is  like  that  of  the  medullary  part  of  the  brain. 

On  each  side  of  the  crista  galli  each  of  them  forms 
a pulpy  enlargement  of  a brownish  colour,  which  is  called 
the  bulb , and  has  been  considered  as  a ganglion. 

From  this  bulb  many  fine  and  delicate  cords  go  off, 
which  proceed  through  the  dura  mater  and  the  foramina 
of  the  cribriform  plate  to  the  Schneiderian  membrane. — 
These  ramifications  of  the  olfactory  nerve  seem  to  receive 
a coat  from  the  dura  mater,  as  they  are  much  more  firm 
after  they  have  passed  through  it.  They  appear  to  be 
arranged  in  two  rows  as  they  proceed  from  the  ethmoid 


Second  and  Third  Pair  of  Nerves.  329 

bone — one  running  near  to  the  septum,  and  the  other  to 
the  opposite  surface  of  the  ethmoid  bone.* 

THE  SECOND  PAIR,  OR  THE  OPTIC  NERVES, 

Originate  from  the  Thalami  Nervorum  Opticorum , and 
appear  on  the  external  and  lower  surface  of  the  brain,  on 
each  side  of  the  sella  turcica. 

Each  of  them  seems  like  a cord  of  medullary  matter, 
inclosed  in  a coat  derived  from  the  pia  mater,  and  has 
not  the  fasciculated  appearance  of  the  other  nerves.  The 
medullary  matter,  however,  appears  to  be  divided  by 
processes  that  pass  through  it,  which  are  derived  from 
the  coat  of  the  nerve. 

They  proceed  obliquely  forward  and  inward,  on  each 
side  of  the  sella  turcica,  in  contact  with  the  brownish 
cineritious  substance,  in  which  the  infundibulum  and  the 
corpora  albicantia  of  Willis  are  situated.f  Anterior  to 
this  substance  they  come  in  contact  with  each  other,  and 
again  separate,  in  such  a way,  that  it  is  an  undecided 
question  whether  they  decussate  each  other,  or  whether 
each  forms  an  angle,  and  is  in  contact  with  the  other  at 
the  angle. 

From  this  place  of  contact,  each  nerve  proceeds  to  its 
respective  foramen  opticum,  where  it  receives  a coat  from 
the  dura  mater,  which  extends  with  it  to  the  eye,  as  has 
been  described  in  the  account  of  that  organ. 

THE  THIRD  PAIR  OF  NERVES 

Are  sometimes  called  Motores  Oculorum , in  consequence 
of  their  distribution  to  several  muscles  of  the  eye.  They 
arise  at  the  inside  of  the  crura  cerebri,  and  make  their  ap- 

* See  Vol.  II.  Page  7. 

Vol.  II.  ' 2 T 


■{■  See  Vol.  I.  p.  334. 


330  Fourth  Pair  of  Nerves. 

pearance  on  the  basis  of  the  brain,  at  the  anterior  part  of 
the  pons  Varolii. 

They  originate  by  numerous  threads,  which  soon  unite 
so  as  to  form  a cord  that  passes  through  the  dura  mater, 
on  each  side  of  the  posterior  clinoid  process,  and  continues 
through  the  cavernous  sinus,  and  the  foramen  lacerum,  to 
the  orbit  of  the  eye. 

Before  this  nerve  enters  the  orbit  it  generally  divides 
into  two  branches,  which  are  situated  one  above  the  other. 
The  Uppermost  Branch  is  spent  principally  upon  the  rectus 
superior  muscle  of  the  eye,  but  sends  a twig  to  the  levator 
palpebrse.  The  Inferior  Branch  is  distributed  to  two  of  the 
recti  muscles,  viz.  the  internus  and  the  inferior,  and  also 
to  the  inferior  oblique.  It  likewise  sends  a twig  to  a 
small  ganglion  in  the  orbit,  called  the  Lenticular  or 
Ophthalmic  Ganglion from  which  proceed  the  fine  nerv- 
ous fibres  that  perforate  the  sclerotica  coat.f 

THE  FOURTH  PAIR  OF  NERVES 

Are  called  the  Pathetic , in  consequence  of  the  expression 
of  the  countenance  produced  by  the  action  of  the  muscle 
on  which  they  are  spent.  They  arise  from  the  side  of  the 
valve  of  the  brain,  below  and  behind  the  Tubercula  Qua- 
drigemina4  and  are  so  small  that  they  appear  like  sewing 
thread.  They  proceed  round  the  crura  of  the  cerebrum, 
and  appear  on  the  surface  between  the  pons  Varolii  and 
the  middle  lobes  of  the  brain.  They  proceed  along  the 
edge  of  the  tentorium  which  they  perforate,  and  passing 

* This  Ganglion,  which  is  considered  as  the  smallest  in  the  body, 
lies  on  the  outside  of  the  optic  nerve,  near  its  entrance  into  the  orbit, 
and  is  generally  surrounded  by  soft  adipose  matter, 

f See  Volume  I.  page  354. 

J Ibid.  Page  336. 


331 


Fifth  Pair  of  Nerves . 

through  the  upper  part  of  the  cavernous  sinus,  enter  the 
orbit  by  the  foramina  lacera.  They  are  exclusively  appro- 
priated to  the  Superior  Oblique  or  Frochlearis  muscle. 

THE  FIFTH  PAIR  OF  NERVES 

Are  called  Trigemina , because  each  nerve  divides  into 
three  great  branches. 

These  nerves  arise  from  the  crura  of  the  cerebellum 
where  they  unite  to  the  pons  Varolii,  by  distinct  fibres, 
which  are  connected  so  as  to  form  a cord  or  nerve,  that  is 
larger  than  any  other  nerve  of  the  brain.  In  many  subjects 
this  cord  seems  partially  divided  into  two  portions,  the 
anterior  of  which  is  much  smaller  than  the  posterior,  and 
appears  softer  at  its  prigin. 

It  passes  into  a short  canal  formed  by  the  dura  mater, 
near  the  anterior  extremity  of  the  petrous  portion  of  the 
temporal  bone,  at  a small  distance  below  the  edge  of  the 
tentorium.  It  is  perfectly  loose  and  free  from  adhesion  to 
the  surface  of  this  canal;  but  it  soon  passes  out  of  it  under 
the  dura  mater,  and  then  adheres  to  that  membrane. 
After  leaving  the  canal  it  expands  like  a fan,  but  still 
consists  of  fine  fibres  which  have  some  firmness.  It  is 
said  that  there  are  seventy  or  eighty  of  these  fibres  in  the 
expansion,  but  they  appear  to  be  more  numerous.  Round 
the  circumference  of  the  expansion  is  a substance  of  a 
brownish  colour,  into  which  the  fibres  enter.  This  is  the 
Semilunar  Ganglion , or  the  Ganglion  of  Gasser , and  from 
it  the  three  nerves  go  off. 

These  nerves  pass  off  from  the  convex  side  of  the 
Ganglion,  and  are  denominated  the  Ophthalmic , the  Su- 
perior Maxillary , and  the  Inferior  Maxillary . 


332 


First  Branch  of  the  Fifth  Pair. 


The  Ophthalmic  Nerve 

Passes  into  the  orbit  of  the  eye  through  the  foramen 
lacerum:  it  there  divides  into  several  branches,  which  are 
called,  from  their  distribution,  the  Frontal  or  Supra - 
Or  bitar,  the  Nasal  and  the  Lachrymal. 

The  Frontal  or  Supra-Orbitar  branch  proceeds  forward 
in  the  upper  part  of  the  orbit,  exterior  to  the  membrane 
which  lines  it,  and  divides  into  two  ramifications.  One  of 
these  is  small,  and  passes  out  of  the  orbit  near  the  pulley 
of  the  superior  oblique,  to  be  spent  upon  the  orbicularis 
muscle  and  the  contiguous  parts. 

The  other  ramification  passes  through  the  Supra-Orbi- 
tary  Foramen,  or  through  the  notch,  which  is  in  the  place 
of  that  foramen,  and  divides  into  a number  of  twigs,  some 
of  which  pass  transversely  towards  the  side  of  the  head, 
and  communicate  with  twigs  from  the  portio  dura.  Most 
of  the  others  extend  upwards  on  the  head.  Some  are  dis- 
tributed to  the  anterior  part  of  the  occipito  frontalis  mus- 
cle, and  the  integuments  of  the  forehead;  others  are  spent 
upon  the  upper  portion  of  the  scalp.  Some  of  the  extreme 
parts  of  these  ramifications  also  communicate  with  the 
portio  dura. 

The  Nasal  Branch  proceeds  obliquely  forward  towards 
the  innei  side  of  the  orbit,  and  sends  a twig  in  its  course 
to  the  lenticular  ganglion.  It  also  sends  off  some  small 
twigs,  to  join  the  ciliary  nerves  which  go  from  the  gang- 
lion. On  the  inside  of  the  orbit  a branch  leaves  it,  which 
proceeds  through  the  Foramen  Orbitare  Internum  Anterius 
to  the  cavity  of  the  cranium,  and  passes  a small  distance 
upon  the  cribriform  plate  of  the  ethmoid  bone,  under  the 
dura  mater,  to  a fissure  in  the  said  plate  near  the  crista 
galli,  through  which  it  proceeds  into  the  cavity  of  the 


333 


& 

Second  Branch  of  the  Fifth  Pair. 

nose.  Here  it  divides  into  twigs,  some  of  which  pass  on. 
the  septum  near  its  amerior  edge,  and  terminate  on  the 
integuments  at  the  end  of  the  nose,  while  others  pass 
down  on  the  inferior  turbinated  bone. 

After  parting  with  the  ramification  to  the  nose,  the 
remainder  of  the  nasal  branch  continues  to  the  internal 
canthus  of  the  eye,  and  sends  twigs  to  the  lachrymal  sac, 
the  caruncula  lachrymalis,  the  eye-lids,  and  the  exterior 
surface  of  the  upper  part  of  the  nose. 

The  Lachrymal  Branch  proceeds  obliquely  forward 
and  outwards,  towards  the  lachrymal  gland.  In  its  course 
it  sends  off  a twig  which  passes  through  the  spheno 
maxillary  fissure,  and  communicates  with  a twig  of  the 
upper  maxillary  nerve,  and  one  or  more  twigs  that  pass  to 
foramina  in  the  molar  bone.  The  main  branch  passes  to 
the  lachrymal  gland,  and  some  twigs  continue  beyond  it 
to  the  contiguous  parts. 

The  Superior  Maxillary  Nerve. 

The  second  branch  of  the  fifth  pair  is  examined  with 
great  difficulty  on  account  of  its  peculiar  situation.  It 
proceeds  from  the  semilunar  ganglion,  and  passes  through 
the  foramen  rotundum  of  the  sphenoid  bone  into  the 
upper  part  of  the  zygomatic  fossa.  In  this  situation  it 
sends  a twig  to  the  orbit  by  the  spheno  maxillary  fissure, 
and  a branch,  called  the  Infra  Or  bitar,  which  appears  like 
the  main  nerve,  as  it  preserves  a similar  direction,  to  the 
infra  orbitar  canal.  At  the  same  place  it  sends  downwards 
two  branches  which  unite  together  almost  immediately 
after  their  origin,  and,  as  soon  as  they  have  united,  enlarge 
into  a ganglion.*  This  ganglion  is  called  the  Spheno - 

* Sometimes  a single  branch  passes  downwards  instead  of  two;  but 
it  forms  a ganglion  in  the  same  place. 


334  Second  Branch  of  the  Fifth  Pair:  or 

Palatine.  It  is  rather  of  a triangular  figure,  and  lies  very 
near  the  spheno-palatine  foramen.  It  gives  off  a posterior 
branch,  which  passes  through  the  pterygoid  foramen  to 
the  cavity  of  the  cranium:  some  branches  which  proceed 
through  the  spheno-palaiine  foramen  to  the  nose,  and  are 
called  the  Splieno- Palatine  or  Lateral  Nasal  Nerves:  and 
an  inferior  branch,  that  proceeds  through  the  posterior 
palatine  canal,  and  is  called  the  Palatine  Nerve. 

The  small  branch,  which  was  first  mentioned,  as  going 
to  the  orbit  by  the  spheno  maxillary  fissure,  divides  into 
two  ramifications.  One  of  them  unites  with  a twig  of  the 
lachrymal  branch  above  mentioned,  and  passes  out  of  the 
orbit,  through  a foramen  in  the  molar  bone,  to  the  face; 
where  it  is  distributed.  The  other  passes  also  through  a 
foramen  of  the  molar  bone,  into  the  temporal  fossa,  and, 
after  uniting  with  twigs  from  the  Inferior  Maxillary 
Nerve,  proceeds  backwards  and  perforates  the  aponeurosis 
of  the  temporal  muscle,  to  terminate  on  the  integuments  of 
the  temporal  region. 

Before  the  Infra  Orbitar  branch  enters  the  canal  of  that 
name,  it  sends  off  two  twigs,  called  Posterior  Dental 
Nerves , which  pass  downwards  on  the  tuberosity  of  the 
upper  maxillary  bone,  and  enter  into  small  canals  in  that 
bone,  that  are  situated  behind  the  Antrum  Maxillare. 
They  subdivide  into  fine  twig9  that  proceed  forward  to  the 
alveoli  of  three  or  four  of  the  last  molar  teeth,  and  pene- 
trate each  of  the  roots  by  a cavity  at  its  extremity.  Twigs 
also  proceed  from  these  nerves  to  the  posterior  part  of  the 
gums  and  the  buccinator  muscle. 

After  the  posterior  dental  nerves  have  left  it,  the  Infra 
Orbitar  nerve  proceeds  forwards  in  the  canal  of  that  name; 
and  near  the  extremity  of  it,  gives  off  the  anterior  dental 
nerve,  which  accompanies  it  for  some  distance,  and  then 


Superior  Maxillary  Nerve.  335 

proceeds  downwards  in  a canal  in  the  bone  anterior  to 
the  antrum  maxiilare.  In  its  course  this  nerve  divides 
into  many  fibres,  which  pass  to  the  roots  of  the  incisor, 
canine,  and  small  molar  teeth,  each  in  its  proper  canal. 
These  dental  branches  sometimes  pass  in  the  antrum 
maxiilare  between  the  lining  membrane  and  the  bones. 
The  Infra  Orbitar  nerve  passes  out  of  the  foramen  upon 
the  cheek,  and  divides  into  several  branches  of  considera- 
ble size,  which  are  distributed  on  the  face  from  the  side  of 
the  nose  to  the  back  of  the  cheek,  and  also  upon  the  under 
eye-lid  and  the  upper  lip. 

The  Pterygoid  Nerve , or  posterior  branch,  passes  back- 
wards, from  the  ganglion  to  a canal  in  the  base  of  the 
pterygoid  process  of  the  Os  Sphenoides,  and  proceeds 
through  it.  After  leaving  this  canal,  it  passes  through  a sub- 
stance almost  as  firm  as  cartilage,  which  closes  the  anterior 
foramen  lacerum,  at  the  basis  of  the  cranium;  and  divides 
into  two  branches.  The  smallest  of  them,  called  the  Vidian 
Nerve , proceeds  with  a small  artery  to  the  small  foramen, 
or  Hiatus  Fallopii,  on  the  anterior  side  of  the  petrous 
portion  of  the  temporal  bone,  and  continues,  through  a 
small  canal,  to  join  the  Portio  Dura  of  the  seventh  pair  in 
the  larger  canal,  called  the  Aqueduct  Fallopius , at  the 
first  turn  in  that  canal. * The  other  branch  of  the  pterygoid 
nerve  proceeds  to  the  Foramen  Caroticum,  and  passes 
through  it,  with  a twig  of  the  sixth  pair,  to  join  the  first 
cervical  ganglion  of  the  Intercostal  Nerve. 

The  Spheno- Palatine , or  Lateral  Nasal  Nerves  consist 
of  several  branches  which  pass  from  the  spheno-palatine 
ganglion,  through  the  spheno-palatine  foramen,  into  the 

* The  late  Mr.  John  Hunter  believed  that  this  nerve  parts  from  the 
portio  dura  at  the  lower  end  of  the  aqueduct,  and  is  the  chorda  tympani. 


336 


Third  Branch  of  the  Fifth  Pair. 

nose.  Some  of  them  are  distributed  to  that  part  of  the 
pituitary  membrane,  which  is  above  the  upper  meatus, 
and  others  to  the  part  which  is  immediately  below  it. 
Some  of  the  branches  which  thus  enter  the  nose  are  spread 
upon  the  septum:  one  among  them  extends  upon  it,  down- 
wards and  forwards,  to  the  anterior  part  of  the  palatine 
process  of  the  upper  maxillary  bone,  where  it  enters  into 
the  foramen  incisivum,  and  terminates  in  a papilla  in  the 
roof  the  mouth.* 

The  Palatine  Branch  proceeds,  through  the  canal  form- 
ed by  the  upper  maxillary  and  palate  bones,  to  the  roof  of 
the  mouth  and  the  soft  palate.  Soon  after  its  origin,  it 
sends  off  a twig  which  proceeds  down  a small  canal  that 
is  behind  it.  It  also  sends  off,  as  it  proceeds  downwards, 
several  twigs  to  that  part  of  the  membrane  of  the  nose 
which  covers  the  inferior  turbinated  bone.  When  it  ar- 
rives at  the  roof  of  the  mouth,  it  divides  into  several 
branches  which  run  forwards,  and  are  distributed  to  the 
membrane  which  lines  the  roof  of  the  mouth.  Some  of  its 
branches  pass  to  the  soft  palate,  the  uvula,  and  the  tonsils; 
small  filaments  pass  into  the  back  part  of  the  upper  jaw. 

The  Inferior  Maxillary  Nerve,  or  the  Third  Brandi 
■/  of  the  Fifth  Pair , 

Passes  through  the  foramen  ovale  into  the  zygomatic 
fossa,  and  divides  into  two  branches , one  of  which  sends 
ramifications  to  many  of  the  contiguous  muscles,  as  the 

* The  curious  distribution  of  this  nerve  appears  to  have  been  known 
to  the  late  John  Hunter,  and  also  to  Cotunnius;  but  it  is  minutely 
described  by  Scarpa,  and  is  delineated  by  Soemmering  in  his  plate 
of  the  nose. — See  “ Observations  on  certain  parts  of  the  Animal  Eco- 
nomy,” by  J.  Hunter,  page  219, — and  also  Scarpa  “ De  Organo  01- 
factus.”  In  this  last  are  some  interesting  observations  relative  to  the 
ducts  of  Steno. 


Lingual  Branch  of  the  Upper  Maxillary  Nerve.  337 

Temporal,  the  Masseter,  the  Buccinator,  the  Pterygoid? 
and  also  to  the  anterior  part  of  the  ear  and  the  side  of  the 
head.  The  other  branch  passes  between  the  pterygoid 
muscles,  and  divides  into  two  ramifications,  one  of  which 
proceeds  to  the  tongue,  and  is  called  the  Lingual  or  Gus* 
tatory , while  the  other  passes  into  the  canal  of  the  lower 
jaw. 

The  Lingual  Nerve  proceeds  between  the  pterygoid 
muscles,  and  in  its  course  is  joined  by  the  chorda  tym- 
pani.  It  continues  forward  between  the  maxillary  gland 
and  the  lining  membrane  of  the  mouth?  and  passes  near 
the  excretory  duct  of  that  gland,  above  the  mylo-hyoideus 
and  the  sublingual  gland,  to  the  under  side  of  the  tongue, 
near  the  point:  it  then  divides  into  a number  of  branches 
which  enter  into  that  body  between  the  genio-hyoideus 
and  lingualis  muscles. — -This  nerve  has  been  supposed  to 
be  particularly  concerned  in  the  function  of  taste,  because 
many  of  its  branches  continue  to  the  upper  surface  of  the 
tongue,  especially  near  the  point.  In  its  course  it  has 
a communication  with  the  ninth  pair  of  nerves,  and  it 
sends  twigs  to  the  membrane  of  the  mouth  and  gums, 
and  the  contiguous  parts. 

After  parting  with  the  lingual  nerve,  the  inferior 
maxillary  continues  to  the  upper  and  posterior  orifice 
of  the  canal  in  the  lower  jaw.  Before  it  enters  this  canal  it 
sends  a branch  to  the  sub-maxillary  gland,  and  to  the  mus- 
cles under  the  jaw.  It  then  enters  the  canal,  attended  by 
bloodvessels,  and  proceeds  along  it  to  the  anterior  maxil- 
lary foramen,  on  the  side  of  the  chin,  through  which 
it  passes  out.  In  this  course  it  sends  twigs  to  the  sockets 
of  the  teeth,  and  generally  supplies  all  the  large  and  one 
of  the  small  grinders.  Before  it  leaves  the  jaw  it  sends  a 

Vor..  II.  2 U 


338  Sixth  and  Seventh  Pair  of  Nerves. 

branch  forwards,  which  supplies  the  remaining  teeth  on 
the  side  to  which  it  belongs.  After  passing  out,  through 
the  anterior  foramen,  it  is  spent  upon  the  muscles  and 
integuments  of  the  front  of  the  cheek,  the  chin,  and  the 
under  lip. 

THE  SIXTH  PAIR  OF  NERVES 

Are  called  Motores  Externi.  They  arise  from  the  com- 
mencement of  the  medulla  oblongata,  and  proceed  for- 
ward under  the  pons  Varolii.  They  proceed  through  the 
dura  mater  on  the  inside  of  the  fifth  pair,  and  appear 
to  pass  through  the  cavernous  sinuses,  but  are  inclosed 
in  sheaths  of  cellular  membrane  while  they  are  in  those 
sinuses.  When  in  this  situation  they  are  near  the  carotid 
arteries,  and  each  nerve  sends  off  one  or  more  very  fine 
twigs,  which  being  joined  by  a twig  from  the  pterygoid 
branch  of  the  fifth  pair,  accompany  the  carotid  artery 
through  the  carotid  canal,  and  then  unite  themselves  to 
the  upper  extremity  of  the  upper  cervical  ganglion  of  the 
intercostal  nerve. 

The  sixth  pair  afterwards  pass  into  the  orbit  of  the 
eye,  each  through  the  foramen  lacerum  of  its  respective 
side,  and  is  spent  upon  the  Rectus  Externus , or  Abductor 
muscle  of  the  eye. 

THE  SEVENTH  PAIR  OF  NERVES 

Comprises  two  distinct  cords  which  have  very  different 
destinations;  and  have,  therefore,  been  considered  as  dif- 
ferent nerves,  by  several  anatomists.  One  of  these  cords  is 
appropriated  to  the  interior  of  the  ear,  and  is  the  proper 
Auditory  Nerve.  The  other  is  principally  spent  upon  the 
face,  and,  therefore,  has  been  called  the  Facial.  They 
have,  however,  more  frequently  been  denominated  the 


Composition  of  the  Seventh  Pair. — Portio  Dura.  339 

Seventh  Pair , and  distinguished  from  each  other,  in  con- 
sequence of  a great  difference  in  their  texture,  by  the 
appellations  of  Portio  Dura  and  Portio  Mollis . 

These  two  cords  pass  off  nearly  in  contact  with  each 
other,  from  the  side  of  the  upper  part  of  the  Medulla  Ob- 
longata, where  it  is  in  contact  with  the  pons  Varolii;  but 
the  Portio  Mollis  can  be  traced  to  the  fourth  ventricle, 
while  the  Portio  Dura  is  seen  to  arise  from  the  union  of 
the  pons  Varolii  with  the  medulla  oblongata  and  the  crura 
Cerebelli.  The  Portio  Dura , at  its  origin,  is  on  the  inside 
of  the  Portio  Mollis. — Between  these  cords  are  one  or 
more  small  fibres,  called  Portio  Media , which  seem  to 
originate  very  near  them,  and  finally  unite  with  the  Portio 
Dura. 

Each  of  the  seventh  pair  of  nerves,  thus  composed, 
proceeds  from  its  origin,  to  the  Meatus  Auditorius  In- 
ternus  of  the  temporal  bone;  and  the  Portio  Dura  divides 
into  fasciculi,  which  proceed  to  the  different  parts  of  the 
organ  of  hearing,  in  the  manner  described  in  the  account 
of  the  ear.* 

The  Portio  Dura  enters  an  orifice  at  the  upper  and 
anterior  part  of  the  end  or  bottom  of  the  Meatus  Audito- 
rius Internus.  This  orifice  is  the  commencement  of  a 
canal,  which  has  been  called  the  Aqueduct  of  Fallopius , 
and  proceeds  from  the  Meatus  Auditorius  Internus  to  the 
external  foramen,  between  the  mastoid  and  stiloid  pro- 
cesses at  the  basis  of  the  cranium.  This  canal  first  curves 
backwards  and  outwards,  near  to  the  upper  surface  of  the 
petrous  bone,  then  forms  an  acute  angle,  and  proceeds 
(backwards  and  downwards)  to  the  stilo-mastoid  fora- 
men, passing  very  near  the  cavity  of  the  tympanum  in  its 
course. 


See  Volume  I,  page  394. 


340  Chorda  Tympani.— Pes  Anserinus. 

The  Portia  Dura , as  it  passes  into  the  canal  from  the 
meatus  internus,  seems  to  receive  an  investment  from  the 
dura  mater.  It  fills  up  the  canal,  but  does  not  appear  to  be 
compressed.  Near  the  angle  it  is  joined  by  the  twig  of 
the  vidian  nerve,  which  proceeds  from  the  pterygoid 
branch  of  the  fifth  pair,  and  enters  the  petrous  bone  by  the 
small  foramen  innominatum  on  its  anterior  surface.  In  its 
course  through  the  canal  it  sends  off  some  very  small 
twigs  to  the  muscles  and  appurtenances  of  the  small 
bones  of  the  ear,  and  to  the  mastoid  cells;  and,  when 
it  has  arrived  almost  at  the  end  of  the  canal,  it  sends  off, 
in  a retrograde  direction,  a small  branch  which  proceeds 
into  the  cavity  of  the  tympanum,  (entering  it  by  a foramen 
at  the  base  of  the  pyramid),  and  crosses  the  upper  part  of 
it,  near  the  membrana  tympani,  between  the  long  pro- 
cesses of  the  Malleus  and  Incus.  This  twig  is  the  Chorda 
Tympani:  it  proceeds  from  the  cavity,  by  a fissure  on  the 
outside  of  the  Eustachian  tube,  to  join  the  lingual  branch 
of  the  fifth  pair,  as  has  been  already  mentioned.* 

The  Portio  Dura,  after  passing  out  of  the  Foramen 
Stylo- Mastoideum,  is  situated  behind  and  within  the  pa- 
rotid gland.  Here  it  gives  small  twigs  to  the  back  of  the 
ear  and  head,  and  to  the  digastric  and  stylo-hyoideus 
muscles.  It  perforates  the  gland  after  sending  filaments 
to  it,  and  then  divides  into  branches  which  are  arranged 
in  such  a manner  that  they  constitute  what  has  been  called 
the  Pes  Anserinus. 

To  describe  the  various  branches  in  this  expansion 
would  be  more  laborious  than  useful.  Some  of  them 

* The  late  John  Hunter  believed  that  the  chorda  tympani  is  merely 
a continuation  of  the  twig  of  the  pterygoid  branch  which  joins  the 
portio  dura  above. — See  Observations  on  certain  parts  of  the  Animal 
Economy,  page  220. 


Composition  of  the  Eighth  Pair  of  Nerves.  341 

are  spread  upon  the  temple  and  the  upper  part  of  the 
side  of  the  head,  and  unite  with  the  supra-orbitar  branches 
of  the  ophthalmic  nerve.  Some  pass  above  and  below  the 
eye,  and  are  distributed  to  the  orbicularis  muscle,  and 
communicate  with  nervous  twigs  that  pass  through  fora- 
mina in  the  malar  bone,  &c.  Some  large  branches  pass 
transversely.  They  cross  the  masseter  muscle,  and  divide 
into  ramifications  which  are  spent  upon  the  cheek  and  the 
side  of  the  nose  and  lips,  and  communicate  with  the  small 
branches  of  the  superior  maxillary  nerve. 

A large  number  of  branches  pass  downwards.  Many  of 
~ them  incline  forwards,  and  are  spent  on  the  soft  parts 
about  the  under  jaw;  while  others  proceed  below  the  jaw 
to  the  superficial  muscles  and  integuments  of  the  upper 
part  of  the  neck,  communicating  with  the  branches  of  the 
contiguous  nerves.* 

THE  EIGHTH  PAIR  OF  NERVES 

Are  very  frequently  denominated  the  Par  Vagum,  on 
account  of  their  very  extensive  distribution. 

They  arise  from  those  portions  of  the  medulla  oblon- 
gata which  are  denominated  the  Corpora  Olivaria.  Each 
nerve  consists  of  a cord,  which  is  anterior,  and  called  the 
Glosso-Pharyngeal;  and  of  a considerable  number  of  small 
filaments,  which  arise  separately,  but  unite  and  form 
another  cord,  the  proper  Par  Vagum.  Associated  with 
these  is  a third  cord,  called  the  Spinal , or  Accessory  Nerve 

* A most  minute  and  laborious  description  of  the  nerves  of  the  face 
was  published  by  the  celebrated  Meckle,  in  the  seventh  volume  of 
Memoirs  of  the  Royal  Academy  of  Sciences  of  Berlin,  for  the  year 
1751,  accompanied  with  a plate,  exhibiting  the  side  of  the  head,  of  three 
times  the  natural  size.  This  is  republished  in  the  Collection  Aca- 
demique:  Partie  Etrangere.— -Tom.  viii. 


342 


Glosso- Pharyngeal  Nerve. 

of  Willis,  which  originates  in  the  great  canal  of  the  spine, 
and,  passing  up  into  the  cavity  of  the  cranium,  goes  out 
of  it  with  these  nerves  through  the  foramen  lacerum. 

The  two  first  mentioned  nerves  proceed  from  their 
origin  to  the  posterior  foramen  lacerum,  and  pass  through 
it  with  the  Internal  Jugular  vein, — 'being  separated  from 
the  vein  by  a small  process  of  bone.  They  are  also  separa- 
ted from  each  other  by  a small  process  of  the  dura  mater. 
In  the  foramen  they  are  very  close  to  each  other;  but  soon 
after  they  have  passed  through  it,  they  separate  and  pro- 
ceed towards  their  different  destinations. 

The  Glosso- Pharyngeal  proceeds  towards  the  tongue, 
between  the  stylo-pharyngeus  and  the  stylo-glossus  mus- 
cles, following  the  course  of  the  last  mentioned  muscle  to 
the  posterior  part  of  the  tongue.  At  the  commencement 
of  its  course  it  receives  a twig  from  the  Portio  Dura  and 
one  also  from  the  Par  Vagum.  It  soon  gives  off  a branch 
which  passes  down  on  the  inside  of  the  common  carotid 
to  the  lower  part  of  the  neck,  where  it  joins  some  twigs 
of  the  intercostal  to  form  the  cardiac  nerves.  Afterwards 
it  sends  off  several  twigs  to  the  muscles  of  the  pharynx 
and  its  internal  membrane,  and  also  some  twigs  which 
unite  with  others  from  the  upper  cervical  ganglion  of  the 
Sympathetic , and  form  a network  that  lies  over  the  anterior 
branches  of  the  external  carotid.  The  Glosso- Pharyngeal 
finally  enters  the  tongue,  at  the  termination  of  the  hyo- 
glossus  muscle;  and  after  sending  branches  to  the  lingualis, 
and  the  various  muscles  inserted  into  the  tongue,  termi- 
nates in  small  ramifications  that  are  spent  upon  the  sides 
and  middle  of  the  root  of  the  tongue,  and  upon  the  large 
papillse. 


Superior  Laryngeal  Branch  of  the  Par  Vagum.  343 


THE  PAR  VAGUM 

Are  slightly  enlarged  after  passing  through  the  foramen 
lacerum.  As  they  descend,  they  adhere  to  the  superior 
ganglion  of  the  intercostal,  and  also  to  the  ninth  pair. 
They  proceed  behind  and  on  the  outside  of  the  carotid, 
and  are  contained  in  the  same  sheath  of  cellular  membrane 
which  incloses  that  artery  and  the  internal  jugular  vein. 
Each  of  these  nerves,  soon  after  it  leaves  the  cranium, 
gives  a twig  to  the  glosso-pharyngeal;  that  soon  after 
it  sends  off  a branch  called  the  Pharyngeal , which  unites 
to  one  from  the  accessory  nerve,  and  to  one  or  more 
from  the  glosso-pharyngeal,  and  proceeds  to  the  middle 
constrictor  of  the  pharynx,  when  it  expands  into  ramifica- 
tions that  form  a plexus  from  which  proceed  a number  of 
small  twigs  that  go  to  the  larynx,  and  some  that  pass  down 
on  the  common  carotid  artery. 

It  then  sends  off,  downward  and  forward,  the  Superior 
Laryngeal  nerve,  which  continues  in  that  direction  behind 
the  carotid  artery,  and  divides  into  an  external  and  inter- 
nal branch. 

The  Internal  Branch , which  is  the  largest,  proceeds 
between  the  os  hyoides  and  the  thyroid  cartilage;  and 
divides  into  numerous  ramifications  which  are  distributed 
to  the  arytenoid  muscles  and  to  the  membrane  which  lines 
the  larynx  and  covers  the  epiglottis.  It  is  said,  that  fine 
twigs  can  be  traced  into  the  foramina,  which  are  to  be 
seen  in  the  cartilage  of  the  epiglottis; — some  ramifications 
can  be  traced  to  the  pharynx; — others  communicate  with 
the  branches  of  the  recurrent  nerve. 

The  External  Branch  sends  twigs  to  the  pharynx,  to 
the  lower  and  inner  part  of  the  larynx,  and  to  the  thyroid 
gland. 


344  Recurrent  Branch  of  the  Par  Vagum . 

In  its  course  downwards,  the  great  nerve  sometimes 
sends  off  a twig,  which  unites  with  one  from  the  ninth 
pair  that  passes  to  the  sterno-hyoidei  and  sterno-thyroidei 
muscles. 

It  uniformly  sends  off  one  or  more  twigs,  which  pass 
into  the  thorax  and  combine  with  small  branches  from 
the  sympathetic  or  intercostal  nerve,  to  form  the  Cardiac 
Plexus , which  sends  nerves  to  the  heart. 

After  entering  the  thorax,  the  right  trunk  of  the  Par 
Vagum  passes  before  the  subclavian  artery;  and  the  left 
trunk  before  the  arch  of  the  aorta;  and  immediately  after 
passing  these  arteries,  each  of  the  nerves  divides  into  an 
anterior  and  posterior  branch. — The  anterior  is  the  con- 
tinuation of  the  Par  Vagum;  the  posterior  is  a nerve  of 
the  Larynx ; which,  from  its  retrograde  course,  is  called 
the  Recurrent  Nerve. 

On  the  left  side  the  Recurrent  Nerve  winds  backwards 
round  the  aorta,  and  on  the  right  side  round  the  subclavian 
artery,  and  proceeds  upwards,  deeply  seated,  on  the  side 
of  the  trachea,  to  the  Larynx.  Soon  after  its  origin  it 
sends  filaments  to  a ganglion  of  the  sympathetic,  to  the 
cardiac  plexus,  and  to  a pulmonary  plexus  soon  to  be 
mentioned.  In  its  course  upwards  it  sends  twigs  to  the 
trachea  and  the  oesophagus.  It  proceeds  behind  the  thyroid 
gland,  and  sends  twigs  to  that  organ.  At  the  lower  part  of 
the  larynx  it  sends  off  a branch  which  communicates  with 
branches  of  the  superior  laryngeal  nerve.  It  also  divides 
into  branches  which  are  spread  upon  the  posterior  crico- 
arytenoid, and  the  arytenoid  muscles;  and  also  upon  the 
lateral  crico-arytenoid  and  the  thyro-arytenoid  muscles, 
as  well  as  upon  the  membrane  which  lines  the  back  part  of 
the  larynx  and  the  contiguous  surface  of  the  pharynx. 


345 


Par  Vagum. — Pulmonary  Plexuses . 

There  is  a difference  in  the  arrangement  of  the  recur- 
reDts  on  the  different  sides,  in  consequence  of  one  winding 
round  the  aorta,  while  the  other  winds  round  the  subcla- 
vian artery. 

After  sending  off  the  recurrents,  each  trunk  of  the 
Par  Vagum  proceeds  behind  the  ramifications  of  the 
trachea;  but  previously  detaches  some  small  branches, 
which  are  joined  by  twigs  from  the  intercostal  and  from 
the  recurrent,  and  form  a plexus  upon  the  anterior  part  of 
the  vessels  going  to  the  lungs.  This  Anterior  Plexus , after 
sending  off  some  minute  branches  to  the  cardiac  nerves 
and  the  pericardium,  transmits  its  branches,  with  the  bron- 
chise  and  the  bloodvessels,  into  the  substance  of  the  lungs. 

Some  of  the  branches  which  proceed  from  the  par 
vagum,  pass  down  on  the  posterior  part  of  the  trachea, 
and  enter  into  the  membrane  which  forms  it,  and  the 
mucous  glands  which  are  upon  it;  and  some  pass  to  the 
oesophagus. 

When  the  par  vagum  is  behind  the  great  vessels  of  the 
lungs,  a number  of  branches  go  off  transversely,  and  are 
also  joined  by  some  fibres  from  the  sympathetic.  These 
form  the  Posterior  Pulmonary  Plexus;  the  ramifications 
from  which  proceed  into  the  substance  of  the  lungs,  and 
are  principally  spent  upon  the  ramifications  of  the  bron- 
chia. It  has  been  said,*  that  the  small  twigs,  into  which 
they  divide,  very  generally  penetrate  into  the  small  rami- 
fications of  the  bronchia,  and  are  spent  upon  their  internal 
membrane. 

Soon  after  sending  off  the  nerves  of  the  pulmonary 
plexus,  the  Par  Vagum  proceed  downwards  upon  the 

* See  Buisson,  in  the  continuation  of  the  Descriptive  Anatomy  of 
Bichat. 

Vol.  II.  2 X 


346  Termination  of  the  Par  Vagum , Is’c. 

oesophagus;  the  left  nerve  being  situated  anteriorly,  and 
the  right  posteriorly.  Each  of  these  nerves  forms  a plexus 
so  as  nearly  to  surround  the  oesophagus,  as  they  descend  on 
it;  but  the  network  is  thickest  on  the  posterior  side.  They 
pass  through  the  diaphragm  with  the  oesophagus,  and  unite 
again  so  as  to  form  considerable  trunks. 

The  Anterior , which  is  the  smallest,  proceeds  along 
the  lesser  curvature  of  the  stomach  to  the  pylorus.  Some 
of  its  fibres  are  spread  upon  the  anterior  side  of  the 
stomach  and  the  lesser  omentum.  Others  of  them  extend 
to  the  left  hepatic,  and  also  to  the  solar  plexus. 

The  Posterior  trunk  sends  branches  to  surround  the 
cardiac  orifice  of  the  stomach.  Many  branches  are  spread 
upon  the  under  side  of  the  great  curvature  of  the  stomach. 
Some  of  them  pass  in  the  course  of  the  coronary  artery  to 
the  c celiac,  and  unite  to  the  hepatic  and  splenic  plexuses; 
and  one  trunk,  which  is  thick  although  short,  proceeds  to 
the  solar  plexus. 

The  Accessory  Nerve  of  Willis, 

Which  has  been  mentioned  as  associated  with  the  eighth 
pair  of  nerves,  within  the  cranium,  has  a very  peculiar 
origin. 

It  arises  by  small  filaments,  which  come  off  from  the 
spinal  marrow,  between  the  anterior  and  posterior  fasciculi 
of  the  cervical  nerves,  and  proceeds  upwards  to  the  great 
occipital  foramen,  between  these  fasciculi.  It  commences 
sometimes  at  the  sixth  or  seventh  cervical  vertebra,  and 
sometimes  about  the  fourth.  It  enters  the  cavity  of  the 
cranium  through  the  foramen  magnum,  and  proceeds  up- 
wards and  outwards,  so  as  to  join  the  eighth  pair  of 
nerves  at  some  distance  from  it3  origin,  and  in  this 
course  it  receives  fiiaments  from  the  medulla  oblongata. 


Different  Functions  of  the  Laryngeal , £s?c.  347 

After  approaching  very  near  to  the  eighth  pair  of 
nerves,  it  accompanies  it  to  the  foramen  lacerum,  and 
passes  out  in  its  own  separate  sheath.  It  then  leaves  the 
eighth  pair  and  descends  towards  the  shoulder,  proceeding 
through  the  sterno-mastoid  muscle.  Soon  after  it  emerges 
from  the  cranium,  it  sends  a ramification  to  the  pharyngeal 
branch  of  the  Par  Vagumt  and  another  to  the  Par  Vagum 
itself.  After  passing  through  the  upper  and  back  part  of 
the  sterno-mastoid  muscle,  it  terminates  in  the  trapezius. 
It  adheres  to  the  ninth  pair  of  nerves  as  it  passes  by  it,  and 
sends  a twig  to  the  sub-occipital  and  some  of  the  cervical 
nerves.  It  also  gives  ramifications  to  the  sterno-mastoid 
muscle  as  it  passes  through  it. 

It  has  already  been  stated  that  the  Laryngeal  and  Recur- 
rent Nerves  appear  to  answer  different  purposes  in 
their  distribution  to  the  Larynx. — When  both  of  the 
recurrent  nerves  are  divided  in  a living  animal,  the 
voice  seems  to  be  lost.  When  the  laryngeal  nerves 
only  are  divided,  the  strength  of  the  voice  remains, 
but  it  is  flatter.  The  recurrent  nerves,  therefore,  seem 
essential  to  the  formation  of  the  voice.  The  laryngeal 
nerves  are  necessary  to  its  modulation. 

The  history  of  the  investigation  of  this  subject  is 
contained  in  Mr.  Haighton’s  paper  in  the  third 
volume  of  Memoirs  of  the  Medical  Society  of 
London. 


348  Ninth  Pair  of  Nerves. — Descendens  Noni. 

THE  NINTH  PAIR  OF  NERVES. 

Each  of  these  nerves  arises  from  the  groove  in  the 
medulla  oblongata,  between  the  corpora  pyramidalia  and 
the  corpora  olivaria.  Three  or  four  fasciculi,  of  distinct 
filaments,  unite  to  form  it.  Thus  composed,  it  proceeds  to 
the  anterior  condyloid  foramen  of  the  occipital  bone,  and 
passes  through  the  dura  mater.  It  seems  firmly  united,  by 
the  cellular  membrane,  to  the  eighth  pair,  and  to  the  first 
ganglion  of  the  sympathetic,  soon  after  it  passes  from  the 
occipital  bone.  It  is  either  connected  to  the  sub-occipital 
nerve  by  a small  ramification,  or  it  joins  a branch  which 
proceeds  from  the  sub-occipital  to  the  cervical,  and  bends 
round  the  transverse  process  of  the  atlas.  It  passes  be- 
tween the  internal  carotid  artery  and  the  internal  jugular 
vein,  and  crosses  the  external  carotid  at  the  origin  of  the 
occipital  artery.  At  this  place  it  generally  sends  down- 
wards a large  branch  which  is  called  the  Descendens  Noni. 
Passing  forwards, it  is  on  the  outside  of  the  posterior  portion 
of  the  digastric  muscle,  and  inclines  downwards;  but  near 
the  tendon  of  the  muscle  it  turns  upwards,  and  proceeds 
on  the  inside  of  the  mylo-hyoideus,  where  it  divides  into 
ramifications,  which,  at  the  anterior  edge  of  the  hyo-glossus 
muscle,  begin  to  enter  into  the  substance  of  the  tongue, 
between  the  genio-glossus  and  the  lingualis  muscles. 

Some  of  the  branches  of  this  nerve  unite  with  those  of 
the  lingual  branch  of  the  fifth  pair.  Others  are  distributed 
to  almost  all  the  muscles  connected  with  the  tongue. 

The  branch  called  Descendens  Noni  passes  down  in 
the  course  of  the  common  carotid  artery,  and  sends 
branches  in  its  progress  to  the  upper  portions  of  the  coraco- 
hvoidei  and  sterno-thyroidei  muscles;  it  unites  with  rami- 


Sub-Occipital , or  Tenth  Pair  of  Nerves.  349 

fications  of  various  sizes  from  the  first,  second  and  third 
cervical  nerves,  which  form  a bow  under  the  sterno-mas- 
toid  muscle,  from  which  ramifications  go  to  the  lower 
portions  of  the  sterno-hyoidei  and  thyroidei  muscles  and 
of  the  coraco-hyoidei. 

OF  THE  CERVICAL  NERVES. 

The  tenth  or  last  pair  of  the  head,  commonly  called 
the  Sub-occipital , may  be  arranged  with  these  nerves, 
because  they  arise,  like  them,  from  the  medulla  spinalis, 
and  are  distributed  to  the  nerves  on  the  neck. 

The  sub-occipital  Nerves 

Arise  on  each  side  of  the  spinal  marrow,  nearly  opposite 
to  the  interval  between  the  great  foramen  of  the  os  occi- 
pitis  and  the  atlas. 

Each  of  these  nerves  consists  of  an  anterior  and  pos- 
terior fasciculus,  or  bundle  of  fibres,  which  pass  outwards 
immediately  under  the  vertebral  arteries,  and  form  a 
ganglion,  from  which  proceeds  an  anterior  and  a posterior 
branch. 

The  anterior  branch  is  united  to  the  second  cervical 
nerve  below,  and  to  the  ninth  nerve,  or  the  hypoglossal, 
above.  It  also  sends  filaments  to  the  upper"  ganglion  of 
the  great  sympathetic  nerve. 

The  posterior  branch  is  spent  upon  the  Recti , the 
Obliqui , and  some  other  muscles  of  the  head. 

The  proper  Cervical  Nerves  consist  of  Seven  Pair;  of  _ 
which  the  first  six  go  off  between  the  vertebrse  of  the 
neck,  and  the  seventh  between  the  last  of  the  neck  and 
the  first  of  the  back. 


350 


First  and  Second  Cervical  Nerves. 


The  first  cervical  Nerve 
Passes  out  between  the  atlas  and  the  Vertebra  Dentata.  It 
originates  from  two  fasciculi,  which  are  connected  to  each 
other  at  a ganglion,  and  then  separate  into  an  anterior 
and  a posterior  branch.* 

The  anterior  branch  is  connected  by  filaments  with  the 
accessory  nerve,  with  the  ninth  pair  of  the  head,  and  with 
the  upper  ganglion  of  the  sympathetic.  It  is  also  connect- 
ed with  the  second  cervical  nerve;  and  sends  some  branches 
to  the  muscles  on  the  anterior  part  of  the  spine. 

The  posterior  branch,  after  communicating  with  the 
posterior  branches  of  the  sub-occipital  and  the  second 
nerves  of  the  neck,  perforates  the  complexus  muscle;  and 
ascending  upon  the  back  of  the  head,  is  distributed  with 
the  occipital  artery. 

THE  SECOND  CERVICAL  NERVE 

Sends  off,  from  its  Anterior  Branch , a twig  which  de- 
scends to  the  lower  cervical  ganglion  of  the  sympathetic, 
and  a considerable  ramification  to  the  third  cervical 
nerve.  It  also  sends  off  some  twigs  to  the  sterno-mastoid 
muscle,  and  others  to  join  the  accessory  nerve.  Some  of 
its  small  ramifications  pass  down  upon  the  external  jugu- 
lar vein,  and  others  unite  with  the  descending  branch  of 
the  ninth  pair  of  the  head.  A small  branch  is  also  con- 
cerned in  the  formation  of  the  phrenic  nerve.  Two  larger 
branches  of  this  nerve  wind  round  the  posterior  edge  of 
the  sterno-mastoid,  and  are  spread  under  the  integuments 

* This  arrangement  is  common  to  the  nerves  of  the  spine.  The 
ganglion  is  formed  by  the  posterior  fasciculus. 


Third  Cervical , and  Phrenic  Nerves . 351 

of  the  anterior,  lateral  and  posterior  parts  of  the  neck  and 
lower  parts  of  the  head;  they  have  a communication  with 
the  portio  dura  of  the  seventh  pair.^ — The  posterior 
branch  of  this  nerve  is  spent  upon  the  extensor  muscles 
of  the  head  and  neck. 

THE  THIRD  CERVICAL  NERVE 

Sends  down,  from  its  Anterior  Branch , the  principal 
trunk  of  the  phrenic  nerve.  It  also  sends  twigs  to  the 
fourth  cervical,  to  the  lower  cervical  ganglion  of  the 
intercostal,  and  to  the  descending  branch  of  the  ninth 
of  the  head.  Some  of  its  branches  unite  with  twigs  of  the 
accessory  nerve,  and  others  are  spent  upon  the  muscles 
and  integuments  of  the  shoulder  and  lower  part  of  the 
neck.  A small  Posterior  Branch  is  spent  upon  the  muscles 
of  the  back  of  the  neck. 

I 

THE  NERVES  OF  THE  DIAPHRAGM 

Are  generally  denominated  the  Phrenic.  The  principal 
root  of  each  of  them  is  commonly  derived  from  the  third 
cervical  nerve,  but  frequently  the  second  and  the  fourth 
cervical  nerves  contribute  to  their  formation;  and  they 
are  sometimes  joined  by  a twig  which  is  derived  from 
the  ninth  pair. 

Each  nerve  proceeds  down  the  neck,  between  the  rectus 
capitis  major  and  the  scalenus  anticus,  and  continues  along 
the  fore  part  of  the  scalenus  anticus;  it  descends  into  the 
thorax  within  the  anterior  end  of  the  first  rib,  between  the 
subclavian  vein  and  the  artery.  It  sometimes  receives  a 
twig  from  the  fifth  cervical  nerve,  and  a twig  passes  be- 

* These  superficial  branches  have  sometimes  been  described  as 
coming  from  a plexus  ; but  they  often  arise  directly  from  the  Second 
Cervical  nerve. 


352  Remaining  Cervical  Nerves. — Brachial  Plexus. 

tween  it  and  the  great  sympathetic.  After  entering  the 
thorax,  they  descend,  attached  to  the  mediastinum,  before 
the  root  of  the  lungs.  In  consequence  of  the  projection  of 
the  point  of  the  heart  to  the  left,  the  course  of  the  left  is  a 
little  different  from  that  of  the  right;  that  of  the  right 
proceeding  in  a more  perpendicular  direction.  When 
they  arrive  at  the  diaphragm,  they  divide  into  many  ra- 
mifications which  have  a radiated  arrangement,  and  ter- 
minate on  the  fibres  of  that  muscle,  both  on  the  upper  and 
lower  surface.  Some  fibres  from  each  nerve  are  continued 
downward,  and  communicate  in  the  abdomen  with  fibres 
from  the  intercostal. 

THE  FOURTH,  FIFTH,  SIXTH,  AND  SEVENTH  CERVICAL 
NERVES, 

May  be  comprised  in  one  description.  They  pass  off 
successively  from  the  Medulla  Spinalis,  between  the 
vertebrae,  like  the  other  nerves.  Their  Posterior  Branches 
are  generally  distributed  to  the  back  of  the  neck,  and  are 
very  small.  Their  Anterior  Branches  are  principally  ap- 
propriated to  the  upper  extremities,  and  are  large.  They 
generally  send  each  a small  twig  to  the  lower  cervical 
ganglion  of  the  intercostal  nerve,  and  a few  small  branches 
to  some  of  the  contiguous  muscles.  They  are  arranged 
and  combined  so  as  to  form  the  network,  now  to  be 
described,  which  is  called  the  Brachial  or  Axillary  Plexus ; 
and,  in  the  formation  of  this  plexus,  they  are  joined  by  the 
first  dorsal  nerve. 

The  BRACHIAL  PLEXUS 

Extends  from  the  lower  part  of  the  side  of  the  neck,  into  the 
arm-pit.  It  commences  in  the  following  manner. The  fourth 


Construction  of  the  Brachial  Plexus.  353 

and  fifth  cervical  nerves  proceed  downwards,  and,  after 
uniting  to  each  other  about  an  inch  and  a half  below  their 
egress  from  the  spine,  they  separate  again,  almost  im- 
mediately, into  two  branches. 

The  sixth  cervical  nerve,  after  passing  downwards,  di- 
vides also  into  two  branches,  one  of  which  unites  with  the 
uppermost  branch  that  proceeds  from  the  union  of  the 
fourth  and  fifth,  and  the  other  with  the  lowermost,  and 
they  all  proceed  downwards. 

The  seventh  cervical  is  joined  by  the  first  dorsal,  which 
proceeds  upwards,  and  unites  with  it  at  a short  distance 
from  the  spine.  The  cord  produced  by  their  junction  soon 
unites  with  one  of  the  cords  above  described.  As  these 
different  cords  proceed  downwards,  they  divide,  and  their 
branches  again  unite.  The  axillary  artery,  which  passes  in 
the  same  direction,  is  surrounded  by  them.  In  this  manner 
the  axillary  plexus  is  often  formed. 

The  muscles  about  the  shoulder,  both  before  and  be- 
hind, are  supplied  by  the  axillary  plexus.  Thus,  it  sends 
branches  to  the  Sub-scapularis,  Teres  Major , and  Latissi- 
mus  Dorsi,  behind;  and  to  the  Pectoralis  Major  and 
Minor , and  the  Mamma , before.  It  also  sends  off  a branch 
called  the  Scapularis , which  commonly  arises  from  the 
upper  part  of  the  plexus,  and  proceeds  through  the  notch 
in  the  upper  costa  of  the  scapula,  to  the  supra  and  infra 
spinatus,  teres  minor,  &c. 

Nerves  of  the  Arm. 

All  the  great  nerves  of  the  arm  are  derived  from  the 
axillary  plexus.  There  are  six  of  them,  which  are  denomi- 
nated The  Musculo  Cutaneus;  The  Median ;*  The  Cubital , 


Vox.  II. 


Sometimes  called  Radial. 

2 Y 


354  Musculo  Cutaneus  and  Median  Nerves. 

or  Ulnar;  The  Internal  Cutaneus;  The  Radial  or  Muscu- 
lar Spiral;  and  the  Circumflex  or  Articular. 

The  musculo  cutaneus,  or  perforating  nerve, 
passes  obliquely  through  the  upper  part  of  the  coraco 
brachialis  muscle.  Before  it  enters  the  muscle,  it  sends 
a branch  to  it.  After  leaving  the  muscle,  it  passes  down 
the  arm  between  the  biceps  and  the  brachialis  internus.,  to 
which  it  also  gives  branches.  It  proceeds  to  the  outside 
of  the  biceps,  and  continues  under  the  median  cephalic 
vein  to  the  anterior  and  external  pari  of  the  fore  arm; 
along  which  it  passes,  under  the  integuments.  On  the 
lower  part  of  the  fore  arm  it  divides  into  many  branches, 
which  extend  to  the  root  of  the  thumb  and  the  back  of 
the  hand,  and  terminate  in  the  integuments. 

The  median  nerve,  which  is  one  of  the  largest  of  the 
arm,  often  proceeds  from  the  axillary  plexus  next  to  the 
musculo  cutaneus;  it  passes  down  the  arm,  very  near  the 
humeral  artery,  within  the  edge  of  the  biceps  flexor 
muscle,  and,  during  this  course,  gives  off  no  branches 
of  any  importance.  After  passing  the  bend  of  the  elbow, 
it  proceeds,  under  the  aponeurosis  of  the  biceps,  between 
the  brachialis  internus  and  the  pronator  teres,  and  con- 
tinues down  near  the  middle  of  the  fore  arm,  between  the 
flexor  sublimis  and  the  flexor  profundus.  At  the  elbow  it 
sends  branches  to  several  muscles  on  the  anterior  side  of 
the  fore  arm,  and  to  the  integuments.  Among  these 
branches  is  one,  called  the  Interosseal  Nerve , which  passes 
down  on  the  anterior  surface  of  the  interosseal  ligament, 
with  the  artery  of  that  name.  This  nerve  sends  branches, 
in  its  course,  to  the  long  flexor  of  the  thumb  and  the 
deep  flexor  oi  the  fingers.  When  it  arrives  at  the  pronator 
qua lirmus,  it  sends  branches  to  that  muscle,  and,  passing 
between  it  and  the  interosseous  ligament,  perforates  the 


Cubital  or  Ulnar  Nerve.  355 

ligament,  and  soon  terminates  on  the  posterior  side  of  the 
wrist  and  hand. 

As  the  median  nerve  proceeds  downwards,  it  be- 
comes more  superficial;  and  continuing-  among  the  tendons 
of  the  flexors  of  the  fingers,  it  gives  off  a branch  which 
is  principally  spent  upon  the  integuments  of  the  palm  of 
the  hand.  This  great  nerve  passes  with  the  tendons  under 
the  annular  ligament;  and  immediately  after,  while  it  is 
covered  bv  the  Aponeurosis  Palmaris , and  by  that  portion 
of  the  artery  which  is  called  Arcus  Sub li mis,  it  divides 
into  branches,  which  separate  from  each  other  at  acute 
angles,  and  subdivide  so  as  to  send  a ramification  to  each 
side  of  the  thumb,  of  the  index,  and  of  the  middle  finger; 
and  to  the  radial  side  of  the  ring  finger. 

The  cubital  or  ulnar  nerve  is  also  of  considerable 
size.  It  passes  down  on  the  inside  of  the  triceps  extensor 
muscle,  to  the  great  groove  formed  by  the  plecranon 
process  and  the  internal  condyle  of  the  os  humeri;  and  in 
this  course  it  often  sends  a branch  to  the  triceps,  and 
some  smaller  twigs  to  the  upper  part  of  tht;  fore  arm. 
From  the  groove  it  proceeds  on  the  anterior  part  of  the 
fore  arm,  between  the  flexor  carpi  ulnaris  and  the  flexor 
sublimis,  to  the  wrist.  At  a small  distance  above  the  wrist 
it  sends  off  a branch,  called  the  Dorsalis , which  passes 
between  the  flexor  ulnaris  and  the  ulna,  to  the  back  of  the 
fore  arm  and  wrist,  where,  after  sending  ramifications  to  the 
integuments  and  contigtious  parts,  it  divides  into  branches 
which  pass  to  the  little  finger  and  the  finger  next  to  it. 
Those  branches  send  off,  in  their  course,  many  twigs 
tvhich  pass  to  the  skin  and  cellular  substance. 

The  ulnar  nerve  then  proceeds  with  the  artery,  over  the 
annular  ligament,  on  the  radial  side  of  the  os  pisiforme, 
and  divides  into  two  branches;  one  of  which  is  superficial, 
and  the  other  deep-seated. 


356  Radial , or  Muscular  Spiral  Nerve . 

The  Superficial  divides  into  two  principal  branches,  an 
external  and  an  internal.  The  external  passes  under  the 
anoneurosis  palmaris;  and,  after  sending  a branch  to  com- 
bine with  one  from  the  median,  and  some  twigs  to  the 
contiguous  muscles,  it  subdivides  into  two  branches,  one 
of  which  goes  to  the  ulnar  side  of  the  ring  finger  and  the 
opposite  side  of  the  little  finger.  The  other  branch  sends 
off  some  twigs  to  the  muscles,  and  proceeds  along  the  ulnar 
side  of  the  little  finger. 

The  Deep-seated  palmar  branch  of  the  ulnar  nerve, 
passes  between  the  muscles  of  the  little  finger,  under  the 
tendons  of  the  flexors,  and  accompanies  the  deep-seated 
arterial  arch  in  the  palm  of  the  hand,  giving  branches  to 
the  interossei,  and  other  contiguous  muscles. 

The  radial  or  muscular  spiral  nerve  is  one  of  the 
largest  nerves  of  the  arm.  It  passes  from  the  axillary 
plejtus  downward,  backward  and  outward,  under  the  tri- 
ceps muscle,  to  the  external  side  of  the  os  humeri.  In 
this  course  it  gives  off  several  branches  to  the  different 
portions  of  the  triceps.  It  also  frequently  gives  off  a large 
branch,  which  passes  downwards  on  the  outside  of  the 
olecranon,  to  the  back  of  the  fore  arm,  and  continues  to 
the  back  of  the  hand,  furnishing  many  branches  which 
terminate  in  the  integuments.  It  then  proceeds  downwards 
between  the  supinator  radii  longus  and  the  brachialis 
internus.  Immediately  after  passing  the  articulation  of  the 
elbow,  it  divides  into  two  branches  denominated  the  Su- 
perficial and  the  Profound.  The  Superficial  soon  joins  the 
radial  artery,  and  proceeds  downwards,  sending  branches 
to  the  contiguous  muscles.  In  its  course  about  the  middle 
of  the  arm,  it  crosses  the  tendon  of  the  supinator  longus, 
and  proceeds  between  it  and  the  tendon  of  the  extensor 
carpi  radialis  iongior;  it  soon  after  divides  into  two 


Internal  Cutaneus  and  Articular  Nerves.  357 

branches,  which  are  principally  distributed  to  the  thumb 
and  for -finger,  and  also  to  the  integuments. 

The  Profound  branch  proceeds  to  the  back  of  the  fore 
arm  under  the  radial  extensor,  and' continues  to  the  back 
of  the  wrist  and  hand.  In  this  course  it  divides  into  two 
branches,  which  are  distributed  to  the  contiguous  muscles 
and  tendons,  and  the  integuments. 

The  internal  cutaneus  nerve  is  the  smallest  of  the 
nerves  which  proceed  from  the  axillary  plexus.  It  de- 
scends in  the  course  of  the  basilic  vein,  and  very  near  it. 
Above  the  elbow  it  divides  into  an  Internal  Branchy 
which  proceeds  over  the  Basilic  Vein , and  separates  into 
branches  that  pass  down  on  the  side  of  the  fore  arm; 
and  an  External  Branch  that  passes  under  the  Median 
Basilic  Veiny  and  continues  down  on  the  anterior  part 
of  the  fore  arm. 

The  articular  or  circumflex  nerve  proceeds  back- 
wards from  the  plexus,  between  the  teres  major  and  minor, 
and  passes  nearly  round  the  body  of  the  os  humeri,  at  a 
small  distance  below  its  head.  It  is  distributed  to  the 
contiguous  muscles  and  to  the  articulation;  but  its  princi- 
pal branches  terminate  in  the  deltoid  muscle. 

THE  DORSAL  NERVES 

Proceed  from  the  cavity  of  the  spine  between  the  dorsal 
vertebrae.  They  are  sometimes  called  Intercostalsy  be- 
cause they  pass  between  the  ribs,  like  the  bloodvessels  of 
that  name.  There  are  twelve  pair  of  them,  and  they  are 
named  numerically,  beginning  from  above. 

These  nerves  proceed  from  the  medulla  spinalis  by  two 
fasciculi  of  fibres— one  from  each  of  its  lateral  portions, 
— the  posterior  fasciculus  is  the  largest.  After  passing 


358 


Dorsal  Nerves* 


through  the  lateral  foramen  and  the  dura  mater,  a ganglion 
is  formed  by  the  posterior  fasciculus:  the  anterior  fascicu- 
lus unites  to  this  ganglion  at  its  external  extremity}  and 
one  nerve  is  formed,  which  almost  immediately  divides 
into  an  anterior  and  a posterior  branch,  of  which  the  an- 
terior is  the  largest. 

The  posterior  branch  proceeds  backwards,  and  is  dis- 
tributed to  the  muscles  of  the  back.  The  anterior  branch 
passes  towards  the  angle  of  the  rib,  in  contact  with  the 
pleura.  Soon  after  its  origin,  this  anterior  branch  sends 
off  two  ramifications  which  unite  to  the  intercostal  nerve, 
at  the  ganglion;  it  then  proceeds  forwards  with  the  blood- 
vessels, between  the  internal  and  external  intercostal  mus- 
cles, in  the  groove  near  the  lower  margin  of  the  ribs;  and 
terminates  on  the  anterior  part  of  the  thorax.  In  its  course 
it  sends  branches,  not  only  to  the  intercostal  muscles  and 
pleura,  but  to  the  other  muscles  and  the  integuments  of 
the  thorax. 

Some  of  the  dorsal  nerves  differ  from  the  others,  as  to 
the  ramificacions  which  they  send  off. 

The  First  Nerve , of  this  order,  joins  the  lower  cervical 
nerves  in  the  axillary  plexus;  but  it  sends  off  the  ramifica- 
tions to  the  sympathetic;  and  also  a branch,  which  passes 
under  the  first  rib,  like  the  other  dorsal  nerves. 

The  Second  Nerve , sends  off  a branch,  which  passes 
through  the  external  intercostal  muscle  into  the  axilla, 
and  combines  there  with  a branch  of  the  cutaneous  nerve, 
being  distributed  to  the  internal  and  posterior  part  of  the 
arm. 

The  third  dorsal  nerve  also  sends  off  a branch,  which 
is  distributed  to  the  axilla  and  the  back  part  of  the  arm. 

These  branches  of  the  second  and  third  dorsal  nerves, 
are  called  intcrcosto-humeral  nerves. 


General  Account  of  the  Lumbar  Nerves.  35,9 

The  lower  dorsal  nerves  supply  the  muscles  and  inte- 
guments of  the  abdomen. 

Of  the  LUMBAR  Nerves. 

There  are  five  pair  of  these  nerves.  The  first  of  them 
passes  off  between  the  first  and  second  of  the  lumbar  ver- 
tebrae, and  the  others  succeed  regularly;  so  that  the  last 
pair  is  situated  between  the  last  lumbar  vertebra  and  the 
sacrum. 

The  first  lumbar  nerves  arise  from  the  medulla  spinalis, 
before  it  forms  the  cauda  equina;  the  other  four  pair  are 
formed  by  the  cauda  equina. 

They  commence  by  anterior  and  posterior  fasciculi, 
which  are  united  at  a ganglion.  From  this  ganglion, 
anterior  and  posterior  branches  go  off,  which  are  very 
different  in  size,  the  anterior  being  the  largest. 

The  posterior  branches  are  distributed  to  the  muscles 
of  the  back.  The  anterior  send  branches  to  the  ganglions 
of  the  sympathetic  nerve,  and  also  communicate  with 
each  other  to  form  the  Lumbar  Plexus , which  is  situated 
on  the  lateral  parts  of  the  bodies  of  the  Lumbar  Vertebrae, 
before  their  transverse  processes,  and  supplies  nerves  to 
the  muscles  of  the  thigh. 

THE  FIRST  LUMBAR  NERVE 

Is  connected,  by  its  anterior  branch,  to  the  last  dorsal  and 
the  second  lumbar.  From  the  same  branch,  ramifications 
go  off  to  the  Quadratus  Lumborum,  and  obliquely  across 
that  muscle,  to  the  lower  part  of  the  abdominal  muscles 
near  the  spine  of  the  ileum. 


Lumbar  Nerves.— -Lumbar  Plexus. 


2M 


THE  SECOND  LUMBAR  NERVE 
Sends  off  a muscular  branch  downwards  and  outwards:  it 
also  sends  off  the  small  branch,  called  the  External  Sper- 
matic., which  passes  down  in  such  a direction,  that  it  per- 
forates the  transversalis  and  the  obliquus  internus  muscles, 
near  their  lower  margin,  at  a small  distance  from  the 
superior  anterior  spine  of  the  ileum,  and  then  proceeds 
within  the  lower  edge  of  the  tendon  of  the  external 
oblique  to  the  abdominal  ring,  through  which  it  passes. 
In  the  male  it  is  distributed  t the  spermatic  cord  and 
scrotum,  and  in  the  female,  to  the  labia  pudendi.  In  the 
female  it  also  sends  a branch  to  the  uterus.^  The  Second 
Lumbar , after  sending  off  these  branches,  passes  down- 
wards, and  joins  the  Third  lumbar  nerve.  From  this 
union  of  the  second  and  third  nerves,  a branch  called  the 
Cutaneus  Medius , which  will  be  soon  described,  proceeds 
downwards. 

After  sending  off  this  branch,  the  united  trunk  of  the 
second  and  third  joins  the  Fourth;  and  from  this  union 
are  sent  off  the  Obturator  Nerve , which  passes  through 
the  aperture  in  the  membrane  that  closes  the  foramen 
thyroideum;  the  Crural  Nerve , which  passes  under  Pou- 
part’s  ligament;  and  a third  branch  that  proceeds  down- 
wards, and  joins  the  Fifth  lumbar  nerve.  The  Fifth  lumbar 
nerve,  with  this  accession  from  above,  descends  into  the 
pelvis,  and  unites  with  the  sacral  nerves. 

This  arrangement  of  the  lumbar  nerves  constitutes  the 
Lumbar  Plexus , which,  as  has  been  already  stated,  fur- 

* The  external  spermatic  often  come3  off  from  the  first  lumbar* 
nefcve. 


Obturator  Nerve. — Crural  Nerve.  361 

nishes  three  nerves  to  the  lower  extremity,  viz.  the  Cu- 
taneus  Medius , the  Obturator , and  the  Crural  Nerve. 

The  Cutaneus  Medius  which  arises  from  the  union  of  the 
second  and  third  nerves,  as  has  been  already  observed, 
proceeds  downwards,  and  frequently  adheres  to  the  crural 
nerve,  for  a short  distance,  near  Poupart’s  ligament,  but 
soon  leaves  it,  and  descends  on  the  inside  of  the  thigh, 
supplying  the  integuments  as  low  as  the  knee. 

THE  OBTURATOR  NERVE 

Descends  into  the  pelvis,  and  passes  out  of  it  at  the  upper 
part  of  the  foramen  thyroideum;  proceeding  downwards 
in  an  internal  direction,  to  be  distributed  on  the  inside  of 
the  thigh. 

This  nerve  is  generally  accompanied  by  the  obturator 
artery  and  vein;  the  artery  being  above,  and  the  vein 
below  it.  When  it  has  arrived  at  the  foramen  ovale  or 
thyroideum,  it  sends  off  a branch  to  the  internal  and  ex- 
ternal obturator  muscles,  and,  after  passing  these  muscles, 
divides  into  two  branches  which  are  distributed  to  the 
muscles  on  the  inside  of  the  thighs,  the  adductors,  the 
pectineus,  the  gracilis,  &c. 

THE  CRURAL  NERVE 

Is  situated  at  first  behind,  and  then  on  the  outside  of  the 
psoas  muscle.  It  passes  under  Poupart’s  ligament  with 
the  great  femoral  vessels,  being  on  the  outside  of  the 
artery. 

It  is  distributed  to  the  integuments,  and  also  to  the 
muscles,  which  are  situated  on  the  anterior  and  internal 
parts  of  the  thigh.  Some  of  its  ramifications  go  off  before 
it  passes  under  Poupart’s  ligament.  Several  of  them  are 
spent  upon  the  integuments,  and  are  therefore  denomina- 
Vol.  II.  2 Z 


362  Crural  Nerve.-— Sacral  Nerves 

ted  Cutaneous. — They  are  distinguished  by  the  terms 
Cutaneus  Anterior , Cutaneus  Internus , 8cc.,  according  to 
their  situations. 

The  deepseated  branches  are  the  largest.  They  are 
principally  spent  upon  the  muscles  on  the  anterior  and 
the  internal  side  of  the  thigh,  viz.  the  four  extensors,  the 
adductors,  the  pectineus,  the  sartorius,  and  the  gracilis. 
Among  these  nerves  there  is  one,  called  the  Saphenus , 
which  has  a different  destination.  It  accompanies  the  great 
artery  of  the  thigh  to  the  place  where  it  perforates  the 
Adductors:  it  there  separates  fro  n the  artery,  and  passes 
over  the  tendon  of  the  Adductors , under  the  sartorius 
muscle;  thence  it  continues,  with  the  great  saphena  vein, 
on  the  inside  of  the  leg,  to  the  internal  ankle;  sending 
branches  to  the  integuments  in  its  course.  It  terminates  ife 
skin  and  cellular  substance  on  the  upper  and  internal  sur- 
face of  the  foot. 

The  SACRAL  Nerves 

Are  composed  of  those  cords  of  the  cauda  equina,  which 
remain  after  the  formation  of  the  lumbar  nerves.  They  are 
frequently  stated  to  consist  of  five  or  six  pair,  four  of 
which  pass  through  the  foramina  of  the  sacrum,  and  the 
fifth  between  the  sacrum  and  the  os  coccygis.*  The  cords 
of  which  they  are  respectively  composed  arise  by  anterior 
and  posterior  fasciculi.  When  they  have  arrived  opposite 
to  the  foramina  of  the  sacrum,  through  which  they  are  to 
pass,  a ganglion  is  formed,  at  which  they  unite,  and  then 
divide  into  anterior  and  posterior  branches.!  The  upper- 
most of  the  anterior  branches  are  large,  and  pass  through 

* The  sixth  pair,  when  they  exist,  proceed  in  a groove  in  the  os 
coccygis. 

I The  ganglions  of  the  fourth  and  fifth  nerves  are  extremely  small, 
and  not  so  near  the  foramina  as  those  of  the  others. 


Sciatic  Plexus.— Pudic  Nerve.  363 

the  anterior  foramina  of  the  sacrum.  The  posterior  are 
small,  and  go  through  the  posterior  foramina. 

The  Posterior  Branches  are  generally  spent  upon  the 
muscles  which  lie  on  the  sacrum,  and  posterior  parts  of 
the  pelvis,  externally. 

The  anterior  branches  of  the  three  first  nerves  send 
ramifications  to  the  sympathetic.  They  unite  to  each  other, 
and  are  joined  by  the  last  lumbar  nerve,  and  by  a branch 
of  the  fourth  sacral,  in  the  formation  of  the  great  sciatic 
nerve.  This  union  constitutes  the  sciatic  plexus. 

The  anterior  branch  of  the  fourth  nerve  transmits 
branches  to  the  sympathetic:  it  also  sometimes  sends  a 
branch  to  the  united  nerves  above,  or  the  sciatic  plexus. 
It  sends  branches  to  the  hypogastric  plexus,  and  to  the 
contiguous  muscles. 

The  fifth  and  sixth  pairs,  which  are  very  small,  termi- 
nate also  in  the  contiguous  muscles  and  in  the  integuments. 

From  the  sciatic  plexus,  or  the  nerves  which  com- 
pose it,  several  smaller  branches  go  off.  There  are  generally 
two  which  pass  off  backwards  through  the  ischiatic  notch, 
and  are  denominated  Gluteal , as  they  are  distributed  to 
the  glutei  muscles.  From  the  lowermost  of  these  a branch 
descends  on  the  thigh. 

The  Pudic  Nerve , which  is  appropriated  to  the  organs 
of  generation,  also  passes  off  from  this  plexus,  and  ap- 
pears to  consist  of  fibres  which  are  derived  from  each  of 
the  nerves  that  compose  it.  It  proceeds  between  the 
sacro-sciatic  ligaments,  and  divides  into  two  branches — an 
inferior  and  a superior.  The  inferior  passes  between  the 
erector  penis  and  the  accelerator  urinse  muscles,  and  is 
distributed  to  those  muscles,  to  the  bulb  of  the  urethra  and 
the  interior  of  that  canal,  to  the  scrotum  and  dartos. 

The  superior  proceeds  along  the  os  pubis  to  the  sym- 


364  Course  of  the  Sciatic  Nerve, 

ph  vsis,  and  passes  between  the  bone  and  the  body  of  the 
penis  to  the  dorsum.  A considerable  branch  accompanies 
the  artery  on  the  dorsum,  and  terminates,  by  many  rami- 
fications. on  the  glans  penis;  after  sending  branches  in  its 
course  to  the  integuments  generally,  and  to  the  prepuce. 

In  females,  the  Inferior  Pudic  Nerve  proceeds  along 
the  external  labia  pudendi  to  the  mons  veneris,  sending  off 
many  ramifications  in  its  course. 

The  Superior  Pudic  Nerve  proceeds,  as  in  males,  along 
the  branch  of  the  pubis  to  the  superior  surface  of  the 
clitoris,  and  terminates  principally  upon  the  extremity  of 
that  organ. 

The  sacral  nerves  unite  in  the  sciatic  plexus  to  form 
the  great  nerve  of  the  lower  extremity,  which  is  next  to 
be  described. 

The  GREAT  SCIATIC  Nerve 
Proceeds  from  the  pelvis  through  the  ischiatic  notch,  be- 
tween the  pyramidalis  and  the  superior  gemellus  muscle: 
it  then  passes  down  to  the  back  part  of  the  thigh,  between 
the  tuberosity  of  the  ischium  and  the  great  trochanter  of 
the  os  femoris;  and  continues  downwards,  inclining  from 
within  outwards,  to  the  ham,  where  it  is  situated  between 
the  tendons  of  the  semi-tendinosus  and  semi-membranosus 
on  the  internal  side,  and  the  tendon  of  the  biceps  on  the 
external.  In  this  course  it  sends  off  branches  to  the  muscles 
on  the  posterior  part  of  the  thigh. 

As  the  great  nerve  passes  down  the  thigh,  it  sends  off 
obliquely,  downwards  and  outwards,  a large  branch  which 
is  called  the  Fibular , that  passes  across  the  head  of  the 
fibula  to  the  external  and  anterior  part  of  the  leg.  The 
place  where  this  branch  separates  from  the  main  nerve 
>s  different  in  different  subjects.  It  continues  in  contact 


Distribution  of  the  Fibular  Nerve.  365 

with  it  for  some  distance,  connected  only  bv  cellular 
membrane. 

THE  FIBULAR  OR  PERONEAL  NERVE 

Proceeds  downwards  on  the  inside  of  the  tendon  of  the 
biceps,  and  crosses  obliquely  to  the  outside  of  the  external 
head  of  the  gastroc  nemius:  it  then  passes  inwards  between 
the  long  peroneus  muscle  and  the  fibula;  and  descend- 
ing between  the  muscles  on  the  front  of  the  leg,  divides 
into  two  branches,  one  of  which  inclines  to  the  exterior 
side  of  the  leg,  and  the  other  preserves  an  internal  situa- 
ti  n.  In  its  course  from  the  great  sciatic  nerve  to  the 
fibula,  it  sends  off  some  superficial  ramifications.  The  two 
branches  into  which  it  divides,  after  passing  over  the 
fibula,  continue  downwards.  The  Internal , after  supplying 
the  muscles  on  the  anterior  part  of  the  leg,  passes  under 
the  annular  ligament  like  the  anterior  tibial  artery;  and  on 
the  upper  part  of  the  foot,  divides  into  two  ramifications, 
one  of  which  proceeds  forwards  near  the  internal  edge  of 
the  foot,  and  the  other  near  the  external;  they  divide 
again,  and  are  distributed  to  the  parts  on  the  upper  surface 
of  the  foot,  one  of  their  ramuli  descending  with  the  con- 
tinuation of  the  anterior  tibial  artery  to  the  sole  of  the 
foot. 

The  External  Branch  of  the  fibular  nerve,  as  it  pro- 
ceeds downwards,  supplies  ramifications  to  the  contiguous 
muscles,  and,  passing  through  the  fascia  on  the  outside  of 
the  leg,  continues  between  it  and  the  skin  towards  the 
foot.  In  this  course  it  generally  divides  into  two  branches 
which  are  spent  upon  the  upper  surface  of  the  foot. 

The  GREAT  SCIATIC  Nerve,  after  the  fibular  nerve 
leaves  it,  continues  do  vn  the  thigh,  between  the  tendons 
oi  the  flexors,  behind  the  great  bloodvessels,  and  of  course 
exterior  to  them. 


i 


366  Distribution  of  the  Tibial  Nerve. 

In  the  ham,  this  great  nerve  takes  the  name  of  POPLI- 
TEAL. and  proceeds  across  the  articulation  of  the  knee, 
between  the  heads  of  the  gastroc  nemii,  to  the  posterior 
side  of  the  tibia:  here  it  passes  through  the  upper  portion 
of  the  soleus  or  gastroc  nemius  internus,  and  continues 
between  it  and  the  long  flexor  of  the  toes,  near  the  Poste- 
rior Tibial  Artery;  descending  with  that  artery  to  the 
hollow  of  the  os  calcis.  In  this  situation  it  has  the  name  of 

POSTERIOR  TIBIAL  NERVE. 

At  the  commencement  of  this  course,  a small  distance 
below  the  internal  condyle  of  the  os  femoris,  it  sends  off  a 
branch  of  considerable  size  called  the  Communicans  Tibia; , 
or  Saphena  Externa , which  passes  down  behind  the 
gastroc  nemii,  and  gradually  inclines  externally,  so  that 
it  is  situated  on  the  external  edge  of  the  tendo  Achillis, 
soon  after  the  commencement  of  that  tendon,  and  pro- 
ceeds behind  the  external  ankle,  near  the  outer  side  of  the 
foot,  to  the  smaller  toes;  distributing  branches  to  the  con- 
tiguous parts.  In  its  course  on  the  back  of  the  leg,  it  sends 
off  a branch  which  unites  with  one  of  the  superficial  rami- 
fications of  the  fibular  nerve,  and  descends  to  the  outer 
part  of  the  fo<  -t. 

The  tibial  Nerve , in  its  course  downwards,  sends 
branches  to  the  contiguous  muscles;  and  a few  twigs  which 
form  a species  of  network  on  the  artery.  In  the  hollow  of 
the  os  calcis  it  sends  off  a superficial  branch  to  the  integu- 
ments of  the  sole  of  the  foot,  which  proceeds  on  the  out- 
side of  the  aponeurosis  plantaris:  it  there  also  divides  into 
branches,  which  are  denominated  the  Internal  and  Exter- 
nal Plantar  Nerves. 

The  Internal  Plantar  Nerve  proceeds  forwards,  along 
side  of  the  tendon  of  the  long  flexor  muscle  of  the  great 


Commencement  of  the  Sympathetic  Nerve.  367 

toe,  giving  off  small  branches  in  its  course.  About  the 
middle  of  the  foot  it  divides  into  four  branches,  one  of 
which  proceeds  to  the  inside  of  the  great  toe;  and  a second 
to  the  angle  formed  by  the  great  toe  and  the  toe  nest  to  it, 
where  it  divides  and  sends  a branch  to  the  opposite  sides 
of  those  toes:  the  other  two  branches  are  distributed  in  a 
similar  manner,  to  the  succeeding  toes.  These  digital 
branches  are  connected  with  each  other  by  small  ramifica- 
tions. 

The  External  Plantar  Nerve  proceeds  with  the  external 
plantar  artery  towards  the  external  side  of  the  foot,  be* 
tween  the  short  flexor  of  the  toes  and  the  flexor  accessorius. 
Near  the  external  edge  of  the  foot,  about  the  posterior 
end  of  the  metacarpal  bones,  it  divides  into  three  branches. 
One  proceeds  to  the  outside  of  the  little  toe;  another  passes 
to  the  angle  between  the  fourth  toe  and  the  little  toe,  and 
divides  into  branches  which  are  distributed  to  the  cor- 
responding sides  of  these  toes.  The  third  branch  proceeds 
more  deeply  in  the  foot,  from  the  external  towards  the 
internal  edge  of  it,  and  is  spent  upon  the  deep  seated 
contiguous  muscles. 

THE  GREAT  SYMPATHETIC  OR  INTERCOSTAL  NERVE 

Commences  in  the  cranium  with  those  small  ramifications 
of  the  pterygoid  branch  of  the  upper  maxillary  nerve,  and 
of  the  sixth  pair,  which  accompany  the  carotid  artery 
through  the  canal  in  the  petrous  portion  of  the  temporal 
bone.  These  small  nerves  form  a network  which  sur- 
rounds the  artery  in  the  canal,  and  gives  rise  to  the 
incipient  sympathetic,  a small  cord  which  passes  down 
close  to  the  nerves  of  the  eighth  and  ninth  pair  of  the 
neck.  Opposite  to  the  second  cervical  vertebra,  this  nerve 
is  swelled  or  dilated,  so  as  to  form  a body  of  a light  red 


368  First  Ganglion , and  other  Cervical 

colour,  which  is  more  than  an  inch  in  length,  and  has  the 
form  of  two  cones  united  to  each  other  at  their  bases. 
This  is  the  Superior  Cervical  Ganglion  of  the  Sympathetic 
Nerve , and  from  it  the  nerve  descends,  behind  the  Par 
Vagum , on  the  front  part  of  the  neck.  This  ganglion  re- 
ceives twigs  from  the  first,  second,  third  and  fourth  pairs 
of  cervical  nerves,  and  also  from  the  eighth  and  ninth 
nerves  of  the  head.  It  sends  off  several  twigs,  which  pass 
behind  the  carotid  artery,  at  its  bifurcation,  and  are  joined 
by  twigs  of  the  Portia  Dura  and  the  Glosso-Pharyngeal 
nerves.  From  these  united  twigs  proceed  very  small  ra- 
mifications, which  accompany  several  branches  of  the  ex- 
ternal carotid  artery,  and  some  of  them  pass  down  with 
the  Common  Carotid. 

This  superior  ganglion  also  furnishes  small  twigs  which 
accompany  the  Glosso-Pharyngeal  to  the  tongue  and  pha- 
rynx. Sometimes  a twig  from  it  passes  on  the  back  part 
of  the  thyroid  gland  to  communicate  with  the  recurrent 
nerve.  From  this  ganglion  go  off  some  small  branches, 
which,  uniting  with  others  from  the  superior  laryngeal 
nerves,  form  the  superior  or  superficial  cardiac  nerve, 
which  will  be  soon  described. 

The  trunk  of  the  Sympathetic  Nerve  descends,  on  the 
front  of  the  neck,  from  this  ganglion,  as  has  been  already- 
stated.  In  its  course  it  receives  very  small  twigs  from 
the  fourth  and  fifth  cervical  nerves,  and  sends  some  very- 
small  twigs  which  appear  to  go  to  the  oesophagus,  and  some 
which  unite  to  the  laryngeal  nerve  and  go  to  the  thyroid 
gland.  Some  twigs,  which  are  larger,  proceed  from  it 
into  the  thorax,  and  go  to  the  cardiac  plexus  hereafter  to 
be  described. 

Opposite  to  the  interval  between  the  fifth  and  sixth 
cervical  vertebrae  it  forms  another  ganglion,  of  an  irregu- 


Ganglions  and  Branches  of  the  Sympathetic.  369 

lar  shape,  much  smaller  than  the  first.  This  ganglion,  in 
different  subjects,  differs  in  size  as  well  as  in  several 
other  respects.  Sometimes  it  is  entirely  wanting,  and 
sometimes  it  is  doubled.  It  is  denominated  the  Middle 
Cervical , or  Thyroid  Ganglion. — When  the  fourth,  fifth, 
and  sixth  cervical  nerves  do  not  send  ramifications  to  the 
sympathetic  nerve  above,  this  ganglion  receives  twigs 
from  them. 

The  Middle  Cervical , or  Thyroid  Ganglion , sends  many 
ramifications  downwards.  Some  of  them  enter  the  thorax 
and  conti ibute  to  the  formation  of  the  Cardiac  Plexus;. 
others  accompany  the  inferior  thyroid  artery,  and,  with 
twigs  from  the  recurrent  nerve,  form  a plexus  which  ex- 
tends towards  the  thyroid  gland.  Some  proceed  down- 
wards before,  and  others  behind,  the  subclavian  artery, 
to  the  next  ganglion;  and  among  them  is  generally  one 
which  may  be  regarded  as  the  trunk  of  the  Sympathetic. 

This  third  Ganglion  is  denominated  the  Inferior  Cervi- 
cal, or  the  First  Thoracic.  It  is  almost  constantly  found 
in  the  same  situation,  viz.  between  the  transverse  process 
of  the  last  cervical  vertebra  and  the  head  of  the  first  rib, 
and  is  partly  covered  by  the  origin  of  the  vertebral  artery. 
It  is  generally  larger  than  the  middle  ganglion.  It  receives 
branches  from  the  sixth  and  seventh  cervical,  and  the  two 
first  dorsal  nerves.  Ramifications  pass  from  it  to  the  par 
vagum  and  recurrent  nerve,  and  also  to  the  cardiac  and 
pulmonary  plexus. 

From  this  ganglion  the  Sympathetic  Nerve  proceeds 
downwards  on  the  side  of  the  spine,  as  will  be  described 
hereafter. 

The  Nerves  of  the  Heart , 

Being  derived  from  branches  which  have  already  been 
mentioned,  are  now  to  be  described. 

Voj..  II,  3 A 


3^0  Branches  of  the  Sympathetic, 

They  arise  principally  from  an  arrangement  of  nerves 
denominated  the  Cardiac  Plexus , or  Plexuses , which  is 
situated  about  the  curve  of  the  aorta,  and  extends,  on  the 
posterior  side  of  it,  from  the  root  of  the  arteria  innomi- 
nata  to  the  bifurcation  of  the  pulmonary  artery.  This 
plexus  is  composed  of  nerves  which  are  principally  form- 
ed by  the  union  of  small  ramifications  that  are  derived 
from  the  three  above  mentioned  ganglions  of  the  Sympa- 
thetic Nerve , and  the  nerve  itself;  and  also  from  the  Par 
Vagum  and  some  of  its  branches. 

These  nerves  are  denominated  the  Cardiac.  They  de- 
scend on  their  respective  sides  of  the  neck,  but  are  some- 
what different  on  the  different  sides.  On  the  right  side  three 
nerves  have  been  described  as  particularly  entitled  to  this 
name,  and  on  the  left  side  but  two. 

The  first  on  the  right  side  is  denominated  Superior  or 
Superfcial  Cardiac  Nerve.  It  generally  arises  by  several 
fine  threads,  which  unite  into  one  delicate  cord  that  passes 
down  by  £he  side  of  the  common  carotid.  When  it  has 
arrived  on  a line  with  the  middle  ganglion,  it  sends  a 
twig  to  the  thyroid  plexus,  and  another  that  communicates 
with  a twig  from  the  par  vagum,  which  continues  down- 
wards on  the  carotid  artery.  After  passing  beyond  the 
ganglion,  it  divides  into  several  branches,  which  unite 
themselves  to  branches  of  the  recurrent  nerve  that  are 
going  to  the  middle  ganglion. 

The  second,  which  is  denominated  the  Middle  Cardiac , 
the  Great  Cardiac , or  the  Deep  Cardiac , is  the  largest  of 
the  three.  It  arises  from  the  Middle  Cervical  or  Thyroid 
Ganglion , by  five  or  six  fine  fibrils,  which  finally  form 
one,  that  passes  before  and  across  the  subclavian;  and  at 
that  place,  as  well  as  lower  down,  it  receives  twigs  rrom 
the  par  vagum:  below  this,  it  is  joined  by  a considerable 


Branches  of  the  Sympathetic . 371 

twig  from  the  recurrent,  and  terminates  in  the  Cardihc 
Plexus , to  which  it  contributes  largely. 

The  third  cardiac  nerve  of  the  right  side  is  called  the 
Inferior  or  the  Small  Cardiac  Nerve.  It  originates  from 
the  third,  or  lower  cervical  ganglion,  by  many  fibrils  which 
unite  into  a smaller  number  that  form  a plexus.  It  crosses 
behind  the  subclavian,  and  proceeds  on  the  outside  of  the 
Arteria  Innominata  to  the  curve  of  the  aorta;  continuing 
between  it  and  the  pulmonary  artery,  to  the  anterior  co- 
ronary plexus.  In  this  course  it  receives  several  fibres 
from  the  recurrent  and  the  par  vagum. 

On  the  left  side  the  first  cardiac  nerve  arises  from  the 
upper  ganglion.  The  second  derives  its  origin  from  the 
two  lower  ganglions. 

The  left  superior  or  superficial  cardiac  nerve  arises  like 
the  right,  by  many  distinct  fibres,  and  proceeds  down- 
wards in  the  same  way.  It  descends  between  the  carotid 
and  the  subclavian,  and  when  it  has  arrived  at  the  place 
where  they  originate  from  the  aorta,  it  divides  into  a 
great  number  of  small  ramifications.  Some  pass  before 
the  aorta,  either  to  join  the  branches  of  the  inferiQr  cardiac, 
or  to  unite  with  the  cardiac  branches  of  the  left  nerve  of 
the  par  vagum.  The  others  proceed  behind  the  aorta,  and 
enter  into  the  common  cardiac  plexus. 

The  second  cardiac  nerve  of  the  left  side  may  be  called 
the  Great  Left  Cardiac , and  has  a double  origin  as  above 
mentioned.  The  principal  branch  in  its  composition  arises 
from  the  lowest  cervical  ganglion,  and  passes  behind  the 
transverse  portion  of  the  subclavian  artery.  Where  the 
inferior  thyroid  arises  from  the  subclavian,  this  branch 
receives  a considerable  number  of  ramifications,  which 
arise  from  the  upper  ganglion,  and  are  interwoven  with 
each  other  before  they  unite  to  it.  It  passes  behind  the 


372  Plexus  formed  by  the  Nerves  of  the  Heart-. 

curve  of  the  aorta,  and  terminates  in  the  great  cardiac 
plexus,  which  it  particularly  contributes  to  form.  Here  it 
is  joined  by  many  fibres  from  the  par  vagum. 

The  Cardiac  Plexus 

Is  situated  principally  behind  the  curve  of  the  aorta,  at  a 
small  distance  above  the  heart.  It  commences  as  high  as 
the  origin  of  the  Arteria  Innominata,  and  extends  down- 
wards to  the  bifurcation  of  the  pulmonary  artery. 

As  has  been  already  mentioned,  it  is  principally  com- 
posed of  branches  from  the  middle  cardiac  nerve  of  the 
right  side,  and  the  inferior  cardiac  nerve  of  the  left;,  but  it 
receives  branches  from  the  superior  cardiac  of  the  left, 
and  sometimes  of  the  right  side.  Some  fibres  of  the 
inferior  cardiac  of  the  right  are  also  united  to  it. 

Many  branches  proceed  from  this  plexus. 

A small  number  pass  upon  the  aorta,  and  seem  to  enter 
into  its  texture.* 

Some  of  them  also  combine  with  the  ramifications  of 
the  Par  Vagum  in  the  anterior  pulmonary  plexus. 

The  majority  proceed  to  the  basis  of  the  heart,  near 
the  origin  of  the  pulmonary  artery  and  the  aorta,  and 
constitute  the  proper  nerves  of  that  organ.  They  accom- 
pany the  coronary  arteries,  and  are  so  arranged  around 
them  that,  by  some  anatomists,  they  have  been  said  to 
form  plexuses,  which  have  been  denominated  Coronary. 

The  sympathetic  nerve,  as  has  been  stated  above, 
proceeds  from  the  ganglion,  called  the  Lower  Cervical , 
or  the  First  Thoracic , before  the  neck  of  the  first  rib.  It 
continues  to  descend,  in  the  same  direction,  along  the 
spine,  exterior  to  the  pleura,  to  the  inferior  part  of  the 
thorax.  Near  the  head  of  each  rib  it  forms  a ganglion, 

* It  has  been  asserted,  that  some  of  the  anatomists  of  Paris  have 
traced  these  nerves  on  the  aorta,  to  a great  distance  from  the  heart! 


Sympathetic  Nerve , and  its  Splanchnic  Branches.  373 

which  unites  with  the  intercostal  nerve  behind  it,  by  two 
branches,  and  thus  forms  an  indirect  communication  with 
the  medulla  spinalis. 

From  several  of  the  uppermost  of  these  ganglions,  small 
twigs  proceed  to  the  pulmonary  plexus,  and  also  to  the 
great  trunk  of  the  aorta,  below  the  curve,  forming  a spe- 
cies of  network,  or  plexus,  upon  it. 

From  the  ganglions  near  the  heads  of  the  fifth  and 
sixth  ribs,  and  from  four  or  five  of  the  ganglions  which 
succeed  them,  small  nerves  arise,  which  proceed  down- 
wards on  the  sides  of  the  bodies  of  the  vertebrae,  and  unite 
into  one  trunk  that  is  denominated  the  Splanchnic  Nerve , 
because  it  is  distributed  to  the  viscera  of  the  abdomen. — 
This  nerve  proceeds  behind  the  crus  of  the  diaphragm,  on 
its  respective  side,  into  the  abdomen.  A second  and  smaller 
nerve,  of  the  same  destination,  called  the  Lesser  Splanch- 
nic Nerve , arises  lower  down,  from  two  or  three  of  the 
lowermost  dorsal  ganglions,  and  penetrates  separately 
into  the  cavity  of  the  abdomen:  it  then  generally  divides 
into  two  branches,  one  of  w'hich  unites  to  the  great 
splanchnic  nerve,  and  the  other  proceeds  to  the  renal 
plexus , soon  to  be  described. 

As  soon  as  the  great  splanchnic  nerve  has  entered  the 
abdomen,  it  divides  into  many  branches,  which  commonly 
form  small  ganglions  on  each  side  of  the  codiac,  but  above 
it.  These  ganglions  are  generally  contiguous;  but  some- 
times they  are  at  a small  distance  from  each  other,  and 
united  by  nerves.  Thev  are,  however,  commonly  spoken  of 
as  one,  and  called  the  semilunar  ganglion.  They  are  of 
irregular  forms,  and  very  different  from  each  other  in  size, 
as  well  as  form.  Those  formed  by  the  splanchnic  nerve  on 
one  side  are  sometimes  different  from  those  on  the  other. 

From  this  assemblage  of  ganglions  proceed  many  small 
nerves,  which  are  woven  together  so  as  to  form  a network 
denominated  the  solar  plexus. 


374  Arrangement  of  the  Nerves  of  the 

This  plexus  is  situated  anterior  to  the  spine  and  this 
erura  of  the  diaphragm;  behind  the  stomach,  and  above 
the  pancreas;  and  is  extended  upon  the  cceliac  and  superior 
mesenteric  arteries.  Some  ramifications  from  the  par  va- 
gum  and  the  phrenic  also  join  it. 

The  lower  part  of  the  solar  plexus,  which  surrounds 
more  immediately  the  cceliac  artery,  is  termed  the  Cceliac 
Plexus.  From  it  networks  of  nerves  extend  upon  the  great 
branches  of  the  artery  to  the  organs  which  they  go  to. 

They  extend  to  the  stomach  (although  it  is  supplied 
by  the  par  vagum)  along  the  superior  coronary  or  gastric 
branch  of  the  hepatic;  and  the  fibres  in  their  composition 
being  spread  upon  the  coats  of  the  stomach,  unite  with 
the  branches  of  the  par  vagum,  which  are  also  spread 
upon  them. 

A similar  network,  denominated  the  Hepatic  Plexus , 
extends  upon  the  Hepatic  Artery , and  from  it  to  the  Vena 
Portarum;  and  accompanies  those  vessels  into  the  sub- 
stance of  the  liver.  It  also  sends  branches  to  the  biliary 
duct  and  gall  bladder;  to  the  stomach  by  the  arteria  gas- 
trica  dextra;  and  to  the  omentum. 

The  Splenic  Artery  is  invested  by  a similar  but  smaller 
arrangement  of  nerves,  denominated  the  Splenic  Plexus. 
In  its  course  to  the  spleen,  this  plexus  sends  some  nerves 
to  the  pancreas;  and  also  to  the  stomach  and  omentum, 
with  the  left  gastric  artery. 

The  superior  mesenteric  artery  is  surrounded  by  a 
network,  which  extends  to  it  directly  from  the  solar 
plexus,  and  is  the  largest  of  all  which  proceed  from  that 
plexus.  The  Mesenteric  Plexus  at  first  nearly  surrounds 
the  artery,  md  proceeds  with  it  between  the  laminae  of 
the  mesentery..  In  this  course  it  sends  branches,  with  the 
arteria  colica  dextra,  to  the  transverse  portion  of  the  colon. 


Abdominal  Viscera . 


375 


Between  the  laminae  of  the  mesentery,  it  sends  ramifica- 
tions with  all  the  branches  of  the  artery,  to  the  small 
intestines  generally;  to  the  ccecum,  and  the  right  portion 
of  the  colon;  as  well  as  to  the  mesenteric  glands. 

From  the  lower  part  of  the  solar  plexus  a network 
proceeds,  on  the  front  of  the  aorta,  to  the  inferior  mesen- 
teric artery,  and  surrounds  it.  Nerves  from  this  plexus 
accompany  the  artery  to  the  left  portion  of  the  colon  and 
the  rectum.  Some  of  their  ramifications  combine  with 
those  of  the  hypogastric  plexus. 

The  Emulgent  Artery  is  attended  by  nerves,  which  are 
arranged  like  a network  on  its  anterior  and  posterior  sur- 
faces, and  are  denominated  the  Renal  Plexus.  They  are 
derived  from  the  solar  plexus,  and  frequently  contain 
small  ganglions.  They  proceed  with  the  artery  to  the 
fissure  of  the  kidney,  and  are  distributed  with  its  different 
ramifications,  in  the  substance  of  the  organ. 

Some  branches  pass  from  them  to- the  renal  gland  with 
the  capsular  artery. 

Before  the  renal  plexus  arrives  at  the  kidney,  it  sends 
off,  from  its  inferior  part,  some  few  fibres,  which,  after 
joining  some  others  from  one  of  the  lumbar  nerves,  ac- 
company the  spermatic  arteries,  and  are,  therefore,  called 
the  Spermatic  Plexus.  In  the  male,  these  fibres  proceed 
through  the  abdominal  ring,  and  many  of  them  go  to  the 
testis,  but  they  are  followed  with  great  difficulty,  ou 
account  of  their  small  size. 

In  the  female,  they  go  to  the  ovary  and  the  fallopian  tube. 

From  the  great  plexuses  above,  a small  network  con- 
tinues downwards  on  the  aorta,  receiving  fibres  from  the 
intercostals  on  each  side;  at  the  great  bifurcation  of  the 
aorta  it  divides,  and  is  joined  on  each  side  by  many  rami- 
fications from  the  third  dorsal  nerves,  which  thus  form  a 


376  Termination  of  the  Sympathetic  Nerve. 

plexus  of  considerable  extent,  that  sends  nerves  to  the 
bladder,  rectum,  and  vesiculae  seminales  in  males;  and  to 
the  uterus  and  vagina,  as  well  as  the  bladder  and  rectum, 
in  females.*  This  is  called  the  Hypogastric  Plexus. 

The  plexuses  above  mentioned  are  derived  from  the 
splanchnic  nerve,  which  came  off  from  the  Sympathetic  in 
the  thorax. 

The  sympathetic  nerve,  after  giving  off  the  lesser 
splanchnic,  is  diminished  in  size,  and  approaches  nearer 
to  the  bodies  of  the  vertebrae.  It  passes  through  the  crura 
of  the  diaphragm,  and  then  proceeds  forwards  and  down- 
wards upon  the  spine,  between  the  tendinous  crura  of 
the  diaphragm  and  psoas  muscle;  near  the  vena  cava  on 
the  right  side,  and  the  aorta  on  the  left.  In  this  course,  it 
generally  receives  one  or  two  small  cords  from  the  anterior 
branch  of  each  of  the  lumbar  nerves:  these  cords  proceed 
downwards  and  forwards,  between  the  bodies  of  the  ver- 
tebrae and  the  psoas  muscle,  and  a ganglion  is  generally 
formed  at  the  place  where  they  join  the  nerve. 

In  its  descent  on  the  lumbar  vertebrae,  the  Sympathetic 
sends  off  several  nerves  that  unite  to  the  network  which 
descends  on  the  aorta  from  the  plexus  above.  After 
passing  over  the  lumbar  vertebrae,  it  descends  into  the 
pelvis,  close  to  the  sacrum,  on  the  inner  side  of  the  great 
foramina:  here  it  also  forms  ganglions,  and  communicates 
with  the  sacral  nerves,  and  likewise  with  the  hypogastric 
plexus.  It  terminates  on  the  os  coccygis,  where  its  minute 
fibres  join  those  of  the  opposite  side. 

* Although  the  testicle  receives  nerves  which  are  derived  from  the 
Sympathetic,  the  penis  and  other  external  parts  of  the  organs  of  genera- 
tion do  not:  the  nerves  which  accompany  the  pudic  artery  being  derived 
from  those  which  unite  to  form  the  great  Sciatic. 


SYSTEM  OF  ANATOMY. 

PART  XI. 

OF  THE  ABSORBENT  VESSELS. 

1 HE  absorbent  vessels  are  small  transparent  tubes,  of  a 
delicate  structure,  which  exist  in  considerable  numbers  in 
almost  every  part  of  the  body. 

These  tubes  originate  upon  the  surfaces  of  all  the 
cavities  of  the  body;  and  of  the  cellular  membrane,  in  all 
the  various  parts  into  which  it  penetrates;  upon  the  inter- 
nal surface  of  the  stomach  and  the  intestines;  and  probably 
upon  the  skin. 

Those  which  originate  in  the  Loxver  Extremities  and 
the  Cavity  of  the  Abdomen , unite  and  form  a large  trunk 
called  the  thoracic  duct,  which  proceeds  through  the 
thorax,  and  terminates  in  the  left  Subclavian  Vein , at  its 
junction  with  the  Internal  Jugular.  Those  of  the  Left 
Upper  Extremity , the  Left  Side  of  the  Head , and  the  con- 
tiguous parts,  form  a trunk  which  terminates  in  the  same 
place.  While  the  remaining  absorbents,  or  those  of  the 
Right  Upper  Extremity , and  the  Right  Side  of  the  Head , 
& c.  also  form  a trunk,  which  terminates  in  the  correspond- 
ing part  of  the  Right  Subclavian  Vein. 

The  absorbent  vessels  of  the  middle  size,  which  arise 
from  the  union  of  the  small  vessels,  and  unite  to  form 

Vol.  U.  3 B 


378  Structure  of  the  Absorbent  Vessels. 

the  larger;  in  their  progress  to  these  large  vessels,  pass 
through  certain  bodies  which  have  been  denominated 
Conglobate  Glands , and  may  be  considered  as  appendages 
of  the  absorbent  system. 

The  absorbent  vessels  are  composed  of  two  coats,  which 
are  thin,  but  dense  and  firm,  and  also  elastic.  The  coats  of 
the  thoracic  duct  may  be  separated  from  each  other.  The 
internal  surface  of  the  exterior  coat  is  fibrous.  The  inter- 
nal coat  is  a delicate  but  strong  membrane. — There  is 
great  reason  to  believe  that  the  above  mentioned  fibres 
are  muscular,  or  at  least  irritable:  for  the  absorbent  ves- 
sels have  been  observed,  by  Haller,  to  contract  upon  the 
application  of  strong  sulphuric  acid.  They  have  also  been 
observed  to  propel  their  contents  with  considerable  rapi- 
dit)7,  by  their  own  contraction,  independent  of  pressure,  or 
of  motion  communicated  by  any  other  body. 

Bloodvessels  are  sometimes  observable  in  the  coats  of 
the  larger  absorbents,  in  injected  subjects.  The  vascularity 
of  these  tubes  may  also  be  inferred  from  the  inflammation 
which  frequently  takes  place  in  them. 

Nerves  have  not  been  traced  into  their  texture;  but  the 
absorbents  seem  to  be  painful  when  they  are  inflamed, 
and,  therefore,  it  is  probable  that  they  are  supplied  with 
nerves. 

The  absorbent  vessels  are  very  generally  supplied  with 
valves,  which  are  much  more  numerous  in  some  of  them 
than  in  others;  and  are  different  in  their  number,  in  the 
same  vessels,  in  different  subjects. 

Very  frequently  there  are  several  valves  in  the  course 
of  an  inch:  sometimes  a valve  will  not  appear  in  the 
course  of  several  inches.  In  the  Thoracic  Duct , the  num- 
ber of  valves  is  very  different  in  different  subjects.  These 
valves  are  folds  or  plaits  of  the  internal  membrane,  and 


Commencement  of  the  Absorbents . 379 

are  of  a semi-circular  form.  There  are  commonly  two  of 
them  together,  originating  from  opposite  sides  of  the 
vessel. 

The  absorbents  are  generally  somewhat  dilated  on  the 
side  of  the  valve  which  is  next  to  their  termination,  and 
this  occasions  their  knotted  appearance  when  they  are 
injected.  The  object  of  this  valvular  structure  seems  to  be 
the  prevention  of  retrograde  motion  of  the  contained  fluid, 
in  consequence  of  lateral  pressure. 

Where  the  different  trunks  of  the  absorbents  open  into 
the  veins,  there  are  one  or  two  valves  to  prevent  the  re- 
gurgitation of  the  blood  into  them. 

The  valves  of  course  prevent  the  injection  of  the 
branches  of  these  vessels  from  their  trunks.— In  some 
animals  the  valves  have  sometimes  been  ruptured,  or 
forced  back;  and  the  absorbents  have  been  injected  in  a 
retrograde  direction.  There  are  but  two  or  three  instances 
upon  record  where  this  has  been  practicable  in  the  Human 
Subject. 

In  consequence  of  the  impracticability  of  injecting  the 
small  branches  from  the  larger,  the  absorbent  vessels 
cannot,  generally,  be  demonstrated  at  their  commence- 
ment, or  origin.  It  is,  however,  to  be  observed,  that 
the  lacteais,  or  Absorbents  of  the  Intestines , appear 
no  way  different  from  other  absorbents;  and  they  have 
been  seen  distended  with  chyle,  from  their  commence- 
ment, in  certain  subjects  who  had  died  suddenly.  Their 
origins  have  been  described  very  differently  by  different 
observers. 

Mr.  Cruikshank  describes  them  as  originating  on  the 
surfaces  of  the  villi,  by  a number  of  very  small  radiated 
branches  with  open  orifices;  which  branches  soon  unite  t? 
form  a trunk. 


380  Conglobate  Glands. 

Lieberkuhn  believed  them  to  commence  in  the  form  of 
an  ampullula. — See  page  108  of  this  volume. 

The  second  Monro  also  believes  that  the  absorbents 
begin  by  very  small  tubes,  with  open  orifices,  in  several 
species  of  fish.^ 

It  is  stated  by  Dr.  Soemmering,  upon  the  authority  of 
Haase,  a German  anatomist,  that  when  mercury  is  forced 
backwards  in  the  absorbent  vessels  of  the  foot  and  the 
heart,  it  has  sometimes  escaped  on  the  surfaces  of  those 
parts.  The  probable  inference  from  these  facts  is,  that 
those  vessels  originate  by  open  orifices  on  the  surfaces 
of  the  heart  and  foot. 

The  bodies  connected  with  the  absorbent  vessels,  which 
are  called  Conglobate  Glands , are  generally  of  a roundish, 
or  irregular  oval  form,  and  somewhat  flattened.  They 
are  of  various  sizes,  from  two  lines  in  diameter  to  more 
than  twelve.  Their  colour  is  frequently  whitish,  but  some- 
times it  is  slightly  inclined  to  red.  They  are  invested  with 
a covering  of  cellular  membrane,  which  appears  like  a 
membranous  coat;  and  they  are  connected  to  the  contigu- 
ous parts  by  a loose  cellular  substance.  When  the  absorb- 
ent vessels  connected  with  these  bodies  approach  near  to 
them,  they  divide  into  a number  of  ramifications,  most 
of  which  enter  into  the  substance  of  the  gland,  while 
some  of  them  run  over  it.  On  the  opposite  side  of  the 
gland  a number  of  branches  go  out,  which  unite  and 
form  trunks  similar  to  those  which  entered  the  gland.  The 
vessels  which  enter  the  gland  are  called  Vasa  Inferential 
and  those  which  go  out  of  it  Vasa  Ejferentia. 

These  vessels  are  generally  much  convoluted  in  the 
substance  of  the  glands,  so  that  those  bodies  sometimes 
appear  like  a mere  convolution  of  absorbent  vessels. 

* See  his  work  on  the  Structure  and  Physiology  of  Fishes,  p.  34. 


Fluid  Contained  in  the  Absorbents.  381 

There  has  been  much  diversity  of  sentiment  respecting 
the  structure  of  these  organs.* 

The  absorbent  vessels,  in  the  different  parts  of  the 
body,  generally  contain  fluids  resembling  those  which  are 
found  in  those  parts.  Mr.  Hewson  opened  the  large 
absorbents  in  many  living  animals  of  different  kinds,  and 
found  that  they  contained  a transparent  fluid,  which  coa- 
gulated when  exposed  to  the  air. 

The  arrangement  of  these  vessels  resembles  that  of  the 
veins  in  several  respects.  Many  of  them  are  superficial; 
but  there  are  also  deep-seated  absorbents  which  accom- 
pany the  bloodvessels. 

* Mr.  Abernethy  states,  that  the  mesenteric  gland  of  the  Whale 
consists  of  large  spherical  bags,  into  which  a number  of  the  lacteals 
open.  Numerous  bloodvessels  are  ramified  on  the  surfaces  of  these 
cysts;  and  injection  passes  from  them  into  the  cyst.  He  also  found 
cells  in  the  glands  of  the  absorbent  vessels,  in  the  groin  and  the  axilla 
of  the  horse. — See  Philosophical  Transactions,  for  1796,  Part  I. 


582 


CHAPTER  I. 

OF  THE  ABSORBENTS  OF  THE  LOWER  EXTREMITIES,  THE 
ABDOMEN,  AND  THE  THORAX. 

Under  this  head  are  arranged  the  ramifications  of  all 
the  vessels  which  unite  to  form  the  Thoracic  Duct. 

SECTION  I. 

Of  the  Absorbents  of  the  Lower  Extremities. 

These  absorbents,  like  the  veins,  are  superficial  and 
deep-seated.  The  Superficial  lie  in  the  cellular  membrane, 
very  near  the  skin;  and  form  an  irregular  network  which 
extends  over  the  whole  limb.  They  are,  however,  most 
numerous  on  the  internal  side. 

The  Deep-seated  acccompany  the  arteries  like  the  veins, 
and  there  are  two  at  least  to  each  artery. 

The  Superficial  Absorbents 

Have  been  injected  from  the  toes  so  as  to  form  a network, 
which  occupies  the  upper  surface  of  the  foot.  They  have 
also  been  injected  in  a similar  manner  on  the  sole.  Those 
en  the  upper  surface  of  the  foot  generally  proceed  up- 
ward on  the  anterior  and  inner  side  of  the  leg;  but  some 
©f  them  pass  on  the  external  side  of  it.  Those  on  the  sole 
are  continued  on  the  back  of  the  leg,  but  communicate 
very  frequently  with  the  anterior  vessels.  Some  of  the 
absorbents  from  the  outside  of  the  foot  and  leg  enter  int* 


383 


Absorbents  of  the  Loiter  Extremity. 

some  of  the  popliteal  glands,  soon  to  be  described;  but  they 
are  not  numerous;  and  the  principal  number  continues  up 
to  the  glands  of  the  groin.  The  absorbents  which  originate 
on  the  surface  of  the  thigh,  as  well  as  those  which  pass 
over  it  from  below,  incline  gradually  along  the  anterior 
and  posterior  surface,  to  the  internal  side  of  it;  on  which 
they  proceed,  in  great  numbers,  and  very  near  to  each 
other,  to  the  inguinal  glands.  Superficial  absorbents  pro- 
ceed also  from  the  buttock  and  lower  part  of  the  back, 
from  the  lower  part  of  the  abdomen,  the  perineum,  and 
the  exterior  of  the  genital  organs,  to  these  glands. 

The  Deep-seated  Absorbents 
Are  named  from  the  arteries  they  accompany. 

The  Anterior  Tibial  Absorbents. 

The  anterior  tibial  artery  is  generally  attended  by  one 
which  comes  with  it  from  the  sole,  and  by  another  which 
commences  on  the  upper  surface  of  the  foot.  The  first 
mentioned  absorbent  continues  with  the  artery.  The  last, 
often  passes  through  an  aperture  in  the  interosseal  liga- 
ment, about  one  third  of  the  distance  from  the  ankle  to 
the  knee,  and  accompanies  the  fibular  artery,  while  the  an- 
terior tibial  artery  is  joined  by  other  absorbents  about  the 
same  place.  In  some  instances  a small  absorbent  gland  oc- 
curs in  this  course,  at  a short  distance  below  the  knee. 

The  Posterior  Tibial  Absorbents 
Have  been  injected  from  the  under  side  of  the  toes.  They 
accompany  the  ramifications  on  the  sole  of  the  foot;  and 
after  uniting,  continue  with  the  main  trunk  up  the  leg, 
where  they  enter  into  the  popliteal  glands. 

The  Peroneal  Absorbents  arise  also  from  the  sole  of  the 
foot,  and  its  external  side.  They  accompany  the  peroneal 


384  Absorbents  of  the  Lower  Extremity. 

artery,  and  terminate  in  the  popliteal  glands,  which  re- 
ceive also  the  absorbents  from  the  knee  and  ham. 

From  these  glands  four  or  five  absorbent  vessels  proceed, 
which  accompany  the  great  bloodvessels  of  the  lower  ex- 
tremity; and,  proceeding  with  them  through  the  aperture 
in  the  tendon  of  the  adductors,  continue  upwards  until 
they  enter  some  of  the  glands  of  the  groin. 

The  glands  of  the  ham  and  groin,  which  are  so  inti- 
mately connected  with  the  absorbents  of  the  lower  extre- 
mity, are  very  different  from  each  other. 

The  Popliteal  Glands , or  those  of  the  Ham,  are  but 
three  or  four  in  number,  and  very  small  in  size.  They 
are  generally  deep  seated,  and  very  near  the  artery. 

The  Inguinal  Glands  vary  in  number,  from  eight  to 
twelve  or  more.  They  are  superficial  and  deep-seated. 
The  superficial  communicate  principally  with  the  superfi- 
cial absorbents.  The  lowermost  of  them  are  at  some  dis- 
tance below  Poupart’s  ligament,  and'  the  uppermost  are 
rather  above  it.  They  are  exterior  to  the  fascia  of  the 
thigh.  Their  number  is  generally  six  or  eight,  while  that 
of  the  deep-seated  is  but  three  or  four. 

The  superficial  absorbents  from  below,  approach  very 
near  to  each  other,  and  enter  these  glands.  They  are 
commonly  distributed  among  three  or  four  of  the  lower- 
most; btit  some  of  them  pass  by  these,  and  proceed  to 
one  that  is  higher  up;  and  sometimes  there  are  absorbent 
vessels  which  pass  to  the  abdomen  without  entering  into 
any  of  the  glands  of  the  groin. 

The  deep-seated  absorbents  pass  into  the  deep-seated 
glands,  which,  as  has  been  already  observed,  are  but  few, 
and  lie  very  near  the  artery  under  the  fascia  of  the  thigh. 
The  two  sets  of  glands  are  connected  to  each  other  by 
many  absorbent  vessels  that  pass  between  them.  The 


Inguinal  and.  External  Iliac  Glands.  385 

vessels  which  finally  go  out  of  these  glands,  are  con- 
siderably less  in  number  than  those  which  enter  into 
them.  They  proceed  under  Poupart’s  ligament,  and,  in 
some  instances,  a large  proportion  of  them  pass  through 
three  glands  which  lie  below  this  ligament,  and  are  often 
so  arranged,  that  they  lie  on  each  side  of  the  great  femoral 
vessels,  and  above  them.  One  very  frequently  is  found  on 
the  inside  of  the  femoral  vein,  in  the  vacuity  between  it 
and  the  internal  part  of  the  ligament.  All  the  absorbents 
of  the  lower  extremity,  however,  do  not  enter  these 
glands.  Some  pass  along  with  the  great  vessels  and  enter 
other  glands  near  the  margin  of  the  pelvis.  Some  also 
descend  a short  distance  into  the  pelvis,  and  unite  with 
vessels  that  are  passing  from  the  pelvis  to  the  plexus  and 
the  glands  that  surround  the  external  iliac. 

The  absorbents  which  proceed  from  the  glands  last 
mentioned,  joined  to  those  which  pass  under  Poupart’s 
ligament,  without  entering  these  glands;  and  some  which 
come  from  the  pelvis;  form  a large  plexus,  which  almost 
surrounds  the  external  iliac  vessels,  and  contains  many 
glands. 

These  External  Iliac  Glands  vary  in  their  number  from 
six  to  ten  or  twelve.  They  lie  on  the  side  of  the  pelvis,  in. 
the  course  of  the  external  iliac  vessels,  and  some  of  them 
are  of  considerable  size.  These  glands,  and  the  plexus  of 
absorbents,  extend  in  the  tract  of  the  iliac  vessels,  to  the 
first  lumbar  vertebra..  In  this  course  they  are  joined  by 
the  plexus  which  comes  from  the  pelvis;  and  soon  after 
they  arrive  at  the  Lumbar  Glands , which  form  a very  large 
assemblage,  that  extends  from  the  bifurcation  of  the  aorta 
to  the  crura  of  the  diaphragm. 

These  glands  lie  irregularly,  on  the  aorta  and  vena 
cava,  and  the  lumbar  vertebrae.  Most  if  not  all  the  ab- 

Vol.  II.  3 C 


386 


Absorbents  of  the  Testicles , 8fc. 

sorbents  above  mentioned  pass  through  some  of  them; 
and  from  the  union  of  these  absorbents,  some  of  the  great 
branches,  which  unite  to  form  the  thoracic  duct,  are 
derived. 

In  this  course  from  the  thigh  to  the  lumbar  glands, 
these  absorbent  vessels  are  joined  by  several  others.  The 
Superficial  Absorbents  of  the  scrotum  commonly  enter  into 
the  upper  inguinal  glands,  and  thus  unite  to  the  great 
body  of  absorbents. 

The  Absorbents  of  the  Testicles  originate  in  the  body, 
and  the  coats  of  the  testicle,  and  in  the  epididymis;  and 
are  remarkably  large  and  numerous.  I hey  proceed  along 
the  spermatic  cord,  through  the  abdominal  ring,  to  the 
lumbar  glands.  These  vessels  are  remarkable  for  the  little 
communication  they  have  with  each  other. 

The  Deep-seated  Absorbents  of  the  Scrotum  accompany 
the  absorbents  of  the  testicle  to  the  lumbar  glands;  but 
those  which  are  superficial  enter  the  upper  inguinal  glands. 

The  Absorbents  of  the  Penis  are  also  deep  seated  and 
superficial.  The  deep-seated  arise  from  the  body  of  the 
penis,  and  accompany  the  internal  pudic  artery  into  the 
pelvis.  The  superficial  absorbents  arise  from  the  prepuce, 
and  pass  along  the  dorsum  of  the  penis.  There  are  fre- 
quently several  trunks  which  receive  branches  from  the 
lower  surface  of  the  penis  in  their  course.  At  the  root  of 
the  penis  they  generally  separate  to  the  right  and  left,  and 
pass  to  the  glands  on  the  respective  sides. 

In  females,  the  absorbents  of  the  interior  of  the  clitoris 
accompany  the  internal  pudic  artery.  Some,  which  arise 
about  the  vagina,  pass  through  the  abdominal  ring  with 
the  round  ligament;  and  others  proceed  to  the  inguinal 
glands. 


Absorbents  of  the  Pelvis  and  the  Kidneys.  38>7 


SECTION  II. 

Of  the  Absorbents  of  the  Abdomen  and  Thorax. 

The  Absorbents  of  the  loxver portions  of  the  parietes  of 
the  Abdomen  and  the  Pelvis  unite  into  trunks  that  follow 
the  epigastric,  and  the  circumflex  iliac,  as  well  as  the  lum- 
bar and  sacral  arteries,  Sic.  They  proceed  to  some  of  the 
glands  which  are  in  the  groin;  or  in  the  external  iliac, 
the  hvpogastric,  or  some  of  the  contiguous  plexuses. 

The  Absorbents  of  the  Wo?nb  are  extremely  numerous; 
and,  in  the  gravid  state,  are  very  large.  Those  which  are 
on  the  neck  and  anterior  part  of  the  uterus,  join  the  hypo- 
gastric plexus.  Those  which  are  on  the  posterior  part  of 
the  body,  accompany  the  spermatic  vessels. 

The  Absorbents  of  the  Bladder  pass  to  small  glands  on 
its  lateral  and  inferior  parts,  and  finally  join  the  hypo- 
gastric plexus. 

The  Absorbents  of  the  Rectum  are  of  considerable  size. 
They  pass  through  glands  that  lie  upon  that  intestine,  and 
unite  with  the  lumbar  plexus. 

The  Absorbents  of  the  Kidney  are  superficial  and  deep- 
seated.  They  are  very  numerous,  but,  in  a healthy  state 
of  the  parts,  are  discovered  with  difficulty.  Cruikshank 
describes  them  as  they  appeared,  filled  with  blood,  in  con- 
sequence of  pressing  upon  the  kidney  when  its  veins 
vrere  full  of  blood.  Mascagni  did  not  inject  the  superficial 
vessels  with  mercury;  but  describes  them  as  they  appear- 
ed when  filled  with  colourless  size,  after  he  had  injected 
the  bloodvessels  of  the  organ  with  the  coloured  fluid. — 
The  deep-seated  absorbents  pass  out  of  the  fissure  of  the 
kidney  with  the  bloodvessels,  and  unite  with  the  superfi- 


388  Lacteals , or  Absorbents  of  the  Intestines. 

cial;  they  proceed  to  the  lumbar  plexus,  and  pass  into 
different  glands. 

Absorbent  vessels  can  be  proved  to  proceed  from  the 
pelvis  of  the  kidney,  and  the  ureters,  by  artifices  analogous 
to  those  above  mentioned. 

The  Glandules  Renales  are  also  supplied  with  absorbents, 
which  are  numerous  in  proportion  to  the  size  of  the 
organs.  They  commonly  join  those  of  the  kidney. 

The  Absorbents  of  the  Intestines 
Have  generally  been  called  LACTEALS,  from  the  white 
colour  of  the  chyle  which  they  contain:  but  there  seems 
no  reason  for  believing  that  they  are  different  in  their 
structure  and  nature  from  the  absorbents  in  other  parts  of 
the  body.  A small  number  of  them  appear  as  if  they 
formed  a part  of  the  structure  of  the  intestines,  and  ori- 
ginated from  their  external  surface,  as  they  do  in  other 
parts  of  the  abdomen;  while  the  principal  part  of  them 
are  appropriated  to  the  absorption  of  the  contents  of  the 
cavity  of  the  intestines. 

The  first  mentioned  absorbents  run  between  the  mus- 
cular and  peritoneal  coats,  and  proceed  for  some  distance 
lengthways  on  the  intestine,  while  the  others  proceed 
for  some  distance  within  the  muscular  coat,  with  the  ar- 
teries; and  after  passing  through  it,  continue  between 
the  laminae  of  the  mesentery. 

Branches  of  these  different  absorbents  are  frequently 
united  in  one  trunk;  so  as  to  prove  that  there  is  no 
essential  difference  between  them. 

The  absorbents  which  come  from  the  internal  surface  of 
the  intestines  commence  in  the  villi.  The  manner  in  which 
they  originate  has  been  the  subject  of  considerable  in- 
quiry, as  has  been  stated  in  the  account  of  the  intestines.*' 


* See  page  108. 


Lacteals , or  Absorbents  of  the  Intestines.  389 

The  lacteals  or  absorbents  of  the  intestines  are  very 
numerous.  They  pass  between  the  laminae  of  the  mesen- 
tery, to  glands  which  are  also  seated  between  those  laminae. 
The  number  of  these  glands  is  very  considerable*,  and 
they  are  various  in  size — some  being  very  minute,  and 
others  eight  or  ten  lines  in  diameter.  They  are  generally 
placed  at  a small  distance  from  each  other,  and  are  most 
numerous  in  that  part  of  the  mesentery  which  is  nearest 
to  the  spine.  They  are  almost  always  at  some  distance 
from  the  intestines.  They  appear  to  be  precisely  like  the 
absorbent  glands,  in  other  places. 

These  absorbent  vessels,  in  their  course  frequently  divide 
into  branches;  which  sometimes  go  to  the  same  gland,  some- 
times to  different  glands,  and  sometimes  unite  with  other 
absorbent  vessels.  As  they  proceed,  they  frequently  enlarge 
in  size.  When  they  have  arrived  near  the  spine,  they  fre- 
quently form  three  or  four  trunks,  and  sometimes  one  or 
two;  which  proceed  in  the  course  of  the  superior  mesente- 
ric artery,  until  they  have  arrived  near  to  the  aorta.  Here 
they  either  pass  into  the  thoracic  duct,  or  descend  and  join 
the  trunks  from  the  inferior  extremities,  to  form  the 
thoracic  duct.  The  absorbents  of  the  great  intestines  are 
not  equal  in  size  to  those  of  the  small;  but  they  are  nu- 
merous. They  enter  into  glands,  which  are  very  near,  and 
in  some  places,  in  contact  with  the  intestine;  and  are  com- 
monly very  small  in  size.  The  vessels  which  arise  from 
the  caecum,  and  the  right  portion,  as  well  as  the  arch  of 
the  colon,  unite  with  those  of  the  small  intestines;  while 
the  vessels  from  the  left  side  of  the  colon,  and  the  rectum, 
proceed  to  the  lumbar  glands. 

The  absorbents  of  the  intestines  are  frequently  injected 

* They  have  been  estimated  between  130  and  150. 


390 


Absorbents  of  the  Stomach . 

with  mercury;  but  the  injection  does  not  proceed  to  theiy 
termination  with  so  much  facility  as  it  does  in  other  ves- 
sels of  the  same  kind.  They  have,  however,  very  often, 
been  seen  in  animals,  who  were  killed  for  the  purpose  after 
eating  milk;  and  in  several  human  subjects  who  died  sud- 
denly during  digestion. — The  description  of  the  origin  of 
the  lacteals,  quoted  in  page  109,  from  Mr.  Cruikshank, 
was  taken  from  a subject  of  this  kind,  of  which  an  account 
is  given  in  his  work  on  the  absorbing  vessels,  p.  59. 

It  is  worthy  of  note,  that  in  several  instances,  in  which 
the  lacteals  were  thus  found  distended  with  chyle,  the 
glands  in  the  mesentery  were  also  uniformly  white. 

The  Absorbents  of  the  Stomach 
are  of  considerable  size,  and  form  three  divisions.  The  ves- 
sels of  the  first  set  appear  upon  both  sides  of  the  stomach, 
and  pass  through  a few  glands  on  the  small  curvature,  near 
the  omentum  minus.  From  these  glands  they  proceed  to 
others,  which  are  larger,  and  which  also  receive  some  of 
the  deep-seated  absorbents  of  the  liver.  The  vessels  from 
these  glands  pass  to  the  thoracic  duct,  near  the  origin  of  the 
cadiac  artery.  The  second  arise  also  on  both  sides  of  the 
stomach,  and  pass  to  the  left  extremity  of  the  great  cur- 
vature to  unite  with  the  absorbents  of  that  side  of  the 
great  omentum.  They  then  proceed  with  the  lymphatics 
of  the  spleen  and  pancreas,  to  the  thoracic  duct.  The  last 
set  pass  off  from  the  right  extremity  of  the  great  curva- 
ture, and  unite  also  with  absorbents  from  the  right  portion 
of  the  omentum.  They  proceed  near  the  pylorus,  and  go 
to  the  thoracic  duct,  with  some  of  the  deep-seated  ab- 
sorbents of  the  liver. 

Although  the  absorbents  of  the  stomach  are  deep-seated, 
as  well  as  superficial,  it  is  a general  sentiment,  that  they 
do  not  contain  chyle  in  the  human  subject;  notwiths^and- 


391 


Absorbents  of  the  Liver. 

ing  chyle  has  been  found  in  the  absorbents  on  the  stomach 
of  dogs,  and  some  other  animals.  It  ought,  however,  to  be 
remembered,  that  Sabatier  has,  in  some  instances,  seen 
white  lines  on  the  stomach,  which  he  supposed  to  be 
lacteals. 

The  Absorbents  of  the  Liver 

Are  especially  interesting,  because  they  have  been  more 
completely  injected  than  those  of  any  other  viscus.  They 
are  deep-seated  and  superficial.  The  superficial  it  has  been 
already  observed  admit  of  injection  in  a retrograde  direc- 
tion, and,  therefore,  can  be  exhibited  most  minutely  ra- 
mified. They  communicate  freely  with  each  other,  and 
also  with  the  deep-seated  vessels,  by  their  small  ramifica- 
tions; so  that  the  whole  gland  has  been  injected  from  one 
large  vessel. 

The  gland  is  so  large,  that  the  absorbents  of  the  superior 
and  inferior  surfaces  proceed  from  it  in  different  direc- 
tions. 

A large  absorbent  is  generally  found  on  the  suspen- 
sory ligament.  This  is  formed  by  the  union  of  a great 
many  branches  that  arise  both  on  the  right  and  left  lobes, 
but  principally  on  the  right.  It  often  passes  through  the 
diaphragm  at  an  interstice  which  is  interior  to  the  xiphoid 
cartilage, and  then  proceeds  through  glandson  the  anterior 
part  of  the  pericardium. 

Several  absorbents  proceed  to  the  lateral  ligaments  on 
each  side,  and  then  pass  through  the  diaphragm.  Some 
of  these  branches  return  again  into  the  abdomen,  and  the 
others  generally  run  forwards  in  the  course  of  the  ribs, 
and  join  those  which  passed  up  from  the  suspensory  liga- 
ment. The  trunk,  or  trunks,  formed  by  these  vessels,  either 
pass  up  between  the  laminte  of  the  mediastinum,  and  ter- 


392  Absorbents  of  the  Liver  and  Spleen. 

minate  in  the  upper  part  of  the  thoracic  duct;  or  they 
accompany  the  internal  mammary  arteries,  and  terminate 
on  the  left  side  in  the  thoracic  duct,  and  on  the  right  in 
the  trunk  of  the  absorbents  of  that  side. 

The  Absorbents  on  the  concave  side  of  the  Liver  are  as 
numerous  as  those  on  the  convex  side.  They  are  also  very 
abundant  on  the  surface  of  the  gall  bladder.  The  greatest 
part  of  them  join  the  deep-seated  vessels. 

The  Deep-seated  Absorbents  proceed  in  considerable 
numbers  from  the  interior  of  the  liver  through  the  porta. 
They  accompany  the  biliary  ducts  and  the  great  blood- 
vessels of  the  organ;  and,  after  passing  through  several 
glands,  near  the  vena  portarum,  terminate  in  the  thoracic 
duct,  near  the  commencement  of  the  superior  mesenteric 
artery. 

Mascagni  states,  that  the  absorbents  of  the  liver  will  be 
distended,  by  injecting  warm  water  into  the  biliary  ducts, 
or  the  vena  portarum. 

He  also  observes,  that  in  those  preparations  in  which 
the  superficial  vessels  are  completely  injected,  in  the  re- 
trograde direction,  the  peritoneal  coat  of  the  liver  appears 
to  be  composed  entirely  of  absorbent  vessels;  and  to  be 
connected  to  the  membrane  within,  by  many  filaments 
which  are  also  absorbent  vessels. 

The  Absorbents  of  the  Spleen 

Are  composed  of  superficial  and  deep-seated  vessels;  but 
they  differ  greatly  from  those  of  the  liver,  in  this  respect, 
that  the  superficial  vessels  are  remarkably  small  in  the 
human  subject. 

Mascagni  however  asserts,  that  when  the  bloodvessels 
of  the  spleen  are  injected  with  size,  coloured  with  ver- 
milion, these  absorbents  will  be  filled  with  colourless 

size. 


Absorbents  of  the  Pancreas.  Thoracic  Duct.  393 

In  the  spleen  of  the  calf  the  superficial  absorbents  are 
remarkably  large. 

In  the  human  subject  the  superficial  absorbents  of  the 
spleen  proceed  from  the  convex  to  the  concave  surface, 
and  there  communicate  with  the  deep-seated  absorbents, 
which  proceed  from  the  interior  of  the  organ  with  the 
bloodvessels. 

These  Deep-seated  Absorbents  are  very  numerous,  and 
also  large.  They  accompany  the  splenic  artery;  and  in 
their  course  pass  through  many  glands,  some  of  which 
are  said  to  be  of  a dark  colour.  The  glands  lie  on  the 
splenic  artery,  at  a short  distance  from  each  other.  The 
absorbents  of  the  spleen  receive  the  absorbents  of  the 
pancreas  in  their  course;  they  unite  with  the  absorbents 
of  the  stomach  and  the  lower  surface  of  the  liver,  and  pass 
with  them  to  the  thoracic  duct. 

Little  has  been  latterly  said  by  practical  anatomists 
respecting 

The  Absorbents  of  the  Pancreas. 

Mr.  Cruikshank  once  injected  them  in  the  retrograde  di- 
rection; he  found  that  they  came  out  of  the  lobes  of  the 
pancreas  in  short  branches  like  the  bloodvessels,  and 
passed  at  right  angles  into  the  absorbents  of  the  spleen,  as 
they  accompanied  the  artery  in  the  groove  of  the  pancreas. 

THE  THORACIC  DUCT, 

Or  common  trunk  of  the  absorbent  system,  is  formed  by 
the  union  of  those  absorbent  vessels  which  are  collected 
on  the  lumbar  vertebrae. 

These  vessels,  as  it  has  been  already  observed,  are 
derived  from  various  sources,  viz. 

Vol.  II. 


394  Commencement  of  the  Thoracic  Duct « 

The  Lower  Extremities;  the  lower  part  of  the  Trunk  of 
the  Body;  the  Organs  of  Generation;  the  Intestines,  with 
the  other  Viscera  of  the  abdomen  and  pelvis,  except  a part 
of  the  liver.  Their  number  is  proportioned  to  the  extent 
of  their  origin:  for,  with  the  numerous  glands  appropriated 
to  them,  they  form  the  largest  absorbent  plexus  in  the 
body,  and  are  spread  over  a considerable  portion  of  the 
aorta  and  the  vena  cava. 

The  manner  in  which  these  vessels  unite  to  form  the 
thoracic  duct,  is  very  different  in  different  subjects;  but  in 
a majority  of  cases  it  originates  immediately  from  three 
vessels,  two  of  which  are  the  trunks  of  the  absorbents  of 
the  lower  extremities,  and  the  other  is  the  common  trunk 
of  the  lacteals  and  the  other  absorbents  of  the  intestines. 

These  vessels  generally  unite  on  the  second  or  third 
lumbar  vertebrae;  and,  in  some  instances,  the  trunk  which 
they  form  dilates  considerably,  soon  after  its  commence- 
ment; in  consequence  of  which  it  was  formerly  called  the 
RECEPTACLE  of  the  CHYLE.  At  first  it  lies  behind 
the  aorta,  but  it  soon  inclines  to  the  right  of  it,  so  as  to 
be  behind  the  right  crus  of  the  diaphragm.  In  the  thorax, 
it  appears  on  the  front  of  the  spine,  between  the  aorta  and 
the  vena  azygos,  and  continues  between  these  vessels 
until  it  has  arrived  at  the  fourth  or  third  dorsal  vertebra. 
It  then  inclines  to  the  left,  and  proceeds  in  that  direction 
until  it  emerges  from  the  thorax,  and  has  arisen  above  the 
left  pleura,  when  it  continues  to  ascend  behind  the  inter- 
nal jugular,  nearly  as  high  as  the  sixth  cervical  vertebra:  it 
then  turns  downward  and  forward,  and,  after  descending 
from  six  to  ten  lines,  terminates  in  the  back  part  of  the  an- 
gle formed  by  the  union  of  the  left  internal  jugular  with 
the  left  subclavian  vein.  Sometimes,  after  rising  out  of  the 
thorax,  it  divides  into  two  branches,  which  unite  before 


395 


Termination  of  the  Thoracic  Duct. 

they  terminate.  Sometimes  it  divides,  and  one  of  the 
branches  terminates  at  the  above  mentioned  angle,  and 
the  other  in  the  subclavian  vein,  to  the  left  of  it. 

The  orifice  of  the  thoracic  duct  has  two  valves,  which 
effectually  prevent  the  passage  of  blood  into  it  from  the 
vena  cava. 

There  are  sometimes  slight  flexures  in  the  course  of 
the  duct;  but  it  generally  inclines  to  the  left,  in  the  upper 
part  of  the  thorax,  as  above  mentioned;  and  is  then  so 
near  the  left  lamina  of  the  mediastinum,  that,  if  it  be  filled 
with  coloured  injection,  it  can  be  seen  through  that  mem- 
brane, when  the  left  lung  is  raised  up  and  pressed  to  the 
right. 

The  duct  sometimes  varies  considerably  in  its  diameter 
in  different  parts  of  its  course.  About  the  middle  of  the 
thorax  it  has  often  been  found  very  small.  In  these  cases 
it  generally  enlarges  in  its  progress  upwards,  and  is  often 
about  three  lines  in  diameter,  in  its  upper  part.  Many 
anatomists  have  observed  it  to  divide  and  to  unite  again, 
about  the  middle  of  the  thorax. 

Absorbents  of  the  Lungs. 

The  absorbents  of  the  lungs  are  very  numerous,  and, 
like  those  of  other  viscera,  are  superficial  and  deep- 
seated. 

The  large  superficial  vessels  run  in  the  interstices  be- 
tween the  lobuli,  and  therefore  form  angular  figures  of 
considerable  size.  In  successful  injections,  the  vacancies 
within  these  figures  are  filled  up  with  small  vessels,  and 
the  whole  surface  appears  minutely  injected. 

Mascagni  observes,  that  the  superficial  vessels  are  very 
visible  when  any  fluid  has  been  effused  into  the  cavity  o f 
the  thorax;  or  when  warm  water  is  injected,  either  into  the 


396 


Absorbents  of  the  Lungs. 

bloodvessels  of  the  lungs,  or  the  ramifications  of  the 
trachea.  Cruikshank  demonstrated  them  by  inflating  the 
lungs  of  a still  born  child;  in  which  case  the  air  passes 
rapidly  into  them. 

The  deep-seated  absorbents  accompany  the  bloodvessels 
and  the  ramifications  of  the  bronchiae.  They  pass  to  the 
dark  coloured  glands,  which  are  situated  on  the  trachea  at 
its  bifurcation;  and  on  those  portions  of  the  bronchiae 
which  are  exterior  to  the  lungs.  The  injection  of  the 
absorbents,  which  pass  to  and  from  these  glands,  seems 
to  prove  that  they  are  of  the  same  nature  with  the  ab- 
sorbent glands  in  general;  notwithstanding  their  colour. 
They  are  numerous,  and  they  vary  in  size;  from  a diameter 
of  two  lines,  to  that  of  eight  or  ten. 

From  these  glands,  some  of  the  absorbents  of  the  left  lung 
pass  into  the  thoracic  duct,  while  it  is  in  the  thorax,  behind 
the  bifurcation  of  the  trachea;  others  proceed  upwards 
and  enter  into  it  near  its  termination;  while  those  of  the 
right  lung  terminate  in  the  common  trunk  of  the  absorbents 
of  the  right  side. 


CHAPTER  II. 

OF  THE  ABSORBENTS  OF  THE  HEAD  AND  NECK;  OF  THE 
UPPER  EXTREMITIES,  AND  THE  UPPER  PART  OF 
THE  TRUNK  OF  THE  BODY. 

The  absorbents  from  the  various  parts  of  the  head  pass 
through  glands,  which  are  situated  on  the  neck,  or  the 
lower  part  of  the  head.  Those  on  the  head  are  the  least 
numerous,  and  also  the  least  in  size.  Some  of  them, 
which  are  generally  small,  lie  about  the  parotid  gland. 
Several  of  them,  which  are  also  small,  are  on  the  occiput 


397 


Glands  of  the  Neck. 

below  and  behind  the  mastoid  process.  Sometimes  there 
are  two  or  three  on  the  cheek,  near  the  basis  of  the  lower 
jaw,  about  the  anterior  edge  of  the  masseter  muscle.  Be- 
low the  lower  jaw,  in  contact  with  the  submaxillary  gland 
and  anterior  to  it,  there  are  always  a number  of  these 
glands,  which  are  generally  small,  but  often  swelled  during 
infancy. 

The  Glands  on  the  Neck  are  the  most  numerous.  Many 
of  them  are  within  the  sterno-mastoid  muscle,  and  ac- 
company the  internal  jugular  vein  and  the  carotid  artery 
down  to  the  first  rib.  Many  also  lie  in  the  triangular 
space  between  the  sterno-mastoid  muscle,  the  trapezius, 
and  the  clavicle;  therefore  it  has  been  truly  said  that  the 
glands  of  the  neck  are  more  numerous  than  those  of  any 
other  part,  except  the  mesentery.  They  are  frequently 
called  Glandules  Concatenates.  It  has  already  been  meni 
tioned  that  the  various  absorbents,  which  are  connected 
with  these  glands,  unite  on  each  side  into  a trunk,  which 
on  the  left  passes  into  the  thoracic  duct,  and  on  the  right 
into  the  common  trunk  of  the  absorbents  of  that  side. 

SECTION  I. 

Of  the  Absorbents  of  the  Head  and  Neck. 

There  is  the  greatest  reason  to  believe  that  the  brain 
and  its  appendages  are  supplied  with  absorbents  like  the 
other  parts.  Some  of  these  vessels  have  been  discovered 
in  the  cavity  of  the  cranium;  but  very  little  precise  infor- 
mation has  as  yet  been  obtained,  respecting  the  extent,  or 
arrangement  of  the  absorbent  system,  in  this  part  of  the 
body. 

The  absorbents  on  the  exterior  of  the  head  are  as  nume- 
rous as  in  other  parts  of  the  body.  On  the  occiput  they 
pass  down,  inclining  towards  the  ear,  and  continue  be- 


398  Absorbents  of  the  Head  and  Neck « 

hind  it  to  the  side  of  the  neck;  behind  the  ear  they  pas, s 
through  several  glands.  From  the  middle  or  temporal 
region  of  the  cranium,  they  pass  with  the  carotid  artery 
before  the  ear,  and  enter  some  small  glands  that  lie  on 
the  parotid;  from  which  they  continue  to  the  neck. 

They  are  on  every  part  of  the  face,  and  unite,  so  that 
their  principal  trunks,  which  are  very  numerous,  pass 
over  the  basis  of  the  lower  jaw,  near  the  facial  artery. 
They  enter  into  glands,  which  are  also  very  numerous, 
immediately  under  the  jaw,  or  which  are  sometimes 
to  be  found  on  the  cheek,  at  the  anterior  edge  of  the 
masseter  muscle.  All  the  absorbents  of  the  exterior  part 
of  the  head  pass  to  the  glands  on  the  side  of  the  neck, 
already  described. 

Those  from  the  interior  of  the  nose  accompany  the 
ramifications  of  the  internal  maxillary  artery,  and  pro- 
ceed to  glands  behind  the  angle  of  the  lower  jaw;  into 
which  glands  also  enter  the  absorbents  of  the  tongue  and 
inner  parts  of  the  mouth. 

The  absorbents  of  the  thyroid  gland,  on  the  left  side, 
pass  down  to  the  thoracic  duct;  those  on  the  right,  unite 
to  the  trunk  of  the  absorbents  on  that  side,  near  its  termi- 
nation. It  has  been  remarked  that  they  can  be  readily  in- 
jected, by  thrusting  the  pipe  into  the  substance  of  the  gland. 

SECTION  II. 

f)f  the  Absorbents  of  the  Arm  and  Upper  Part  of  the 
Trunk. 

The  absorbents  of  the  arm  are  superficial  and  deep- 
seated,  like  those  of  the  lower  extremity. 

The  superfcial  absorbents  have  been  injected  on  the 
anterior  and  posterior  surfaces  of  the  fingers  and  the 
thumb,  near  their  sides.  On  the  back  of  the  hand  they 
are  very  numerous,  and  increase  considerably  in  their 


Absorbents  of  the  Hand,  and  Arm . 399 

progress  up  the  fore  arm.  As  they  proceed  upwards,  they 
incline  towards  the  anterior  surface  of  the  fore  arm;  so 
that  by  the  time  they  have  arrived  at  the  elbow,  almost  all 
of  them  are  on  the  anterior  surface.  The  absorbents  on 
the  anterior  part  of  the  hand  are  not  so  numerous  as  those 
on  the  back.  Sometimes  there  are  digital  branches  from 
the  fingers,  and  an  arcus  in  the  palm;  but  this  bow  is  not 
formed  by  one  large  absorbent,  analogous  to  the  ulnar 
artery.  On  the  contrary,  its  two  extremities  are  continued 
over  the  wrist,  and  pass  on  the  fore  arm  like  the  absor- 
bents. 

At  the  elbow,  some  of  them  often  pass  into  one  or  two 
small  glands,  which  are  very  superficial;  but  the  whole  of 
the  absorbents,  somewhat  reduced  in  number,  as  some  of 
them  unite  together,  pass  along  with  the  bloodvessels  into 
the  hollow  of  the  arm  pit;  where  they  enter  the  axillary- 
glands.  There  are  generally  one  or  more  vessels  which 
pass  in  the  course  of  the  cephalic  vein,  between  the  pecto- 
ral and  the  deltoid  muscle,  and  enter  into  some  of  the 
glands  under  the  clavicle. 

There  are  almost  always  several  glands  in  and  near  the 
axilla.  Some  of  them  are  very  near  the  great  bloodvessels; 
sometimes  one  or  more  of  them  are  much  lower;  some- 
times they  are  to  be  "found  under  the  pectoral  muscle. 
They  are  commonly  not  so  large  as  those  of  the  groin, 
and  are  surrounded  with  fat. 

The  deep  seated  absorbents  originate  also  at  the  fingers, 
and  soon  accompany  the  branches  of  the  arteries.  Those 
which  attend  the  radial  artery,  originate  on  the  back  of 
the  hand,  and  also  in  the  palm,  where  thev  are  associated 
with  the  arcus  profundus.  They  go  up  with  the  radial 
artery  to  the  elbow,  and  sometimes  pass  through  a small 
gland  about  the  middle  of  the  fore  arm. 

Those  which  attend  the  ulnar  arterv,  commence  under 


400  Absorbents  of  the  Upper1  Part  of  the  Trunk. 

the  aponeurosis  palmaris,  and  go  with  the  artery  to  the 
elbow;  at  the  bend  of  the  elbow  they  are  generally  joined 
by  one  or  more,  which  accompany  the  interosseal  artery; 
there  they  unite,  so  as  to  form  several  trunks  which  pass 
up  to  the  axilla  with,  the  humeral  artery.  They  sometimes 
pass  through  one  or  two  glands,  which  are  near  the  elbow; 
and  they  receive  in  their  course,  deep  seated  branches 
from  the  muscles  on  the  humerus. 

The  absorbents  from  the  anterior  and  external  part  of 
the  thorax,  and  the  upper  part  of  the  abdomen,  also  proceed 
to  the  axilla,  and  enter  into  the  glands  there;  those  which 
are  deep-seated,  joining  the  deep  seated  vessels.  The  ab- 
sorbents of  the  mammae  pass  to  the  same  glands;  and 
when  they  are  affected  with  the  virus  of  cancer,  can  often 
be  perceived,  in  their  course,  in  the  living  subject. 

The  absorbents  of  the  uppermost  half  of  the  back,  and 
those  of  the  back  of  the  neck,  go  likewise  to  the  axilla. 

The  absorbent  vessels,  collected  from  these  various 
sources, proceed  from  the  exterior  to  the  innermost  glands, 
but  with  a considerable  diminution  of  their  number;  they 
accompany  the  subclavian  vein,  and  are  reduced  to  one  or 
two  trunks,  that  generally  unite  before  their  termination. 
On  the  left  side , the  absorbents  of  the  head  and  neck 
generally  open  into  the  thoracic  duct,  as  has  been  already 
observed;  and  those  of  the  left  arm  also  open  into  the 
thoracic  duct,  or  into  the  subclavian  vein  very  near  it. 
On  the  right  side  the  absorbents  from  each  of  these  parts 
empty  into  the  common  trunk,  which  often  is  formed  by 
the  union  of  large  vessels,  from  four  sources;  viz.  the 
Head,  the  Thyroid  gland,  the  right  Arm,  and  the  right  ca- 
vity of  the  Thorax,  &c.  The  diameter  of  the  trunk  is  very 
considerable;  but  it  is  often  not  more  than  half  an  inch  in 
length.  It  generally  opens  into  the  right  subclavian  vein, 
at  the  place  where  it  unites  to  the  right  internal  jugular. 


Facts  relating  to  Cutaneous  Absorption.  401 

Two  respectable  physiologists  of  Europe  (M.  Seguin,  of 
Paris,  and  the  late  Dr.  Currie,  of  Liverpool)  have 
doubted  whether  absorption  takes  place  on  the  exter- 
nal surface  of  the  skin.* — This  question  has  been 
examined  in  a very  interesting  manner  by  several 
graduates  of  the  university  of  Pennsylvania,  who  chose 
it  for  the  subject  of  their  inaugural  theses;  viz.  Drs. 
Rousseau,  Klapp,  Daingerfield,  Mussey,  and  J.  Bradner 
Stewart. 

The  three  first  of  these  gentlemen  state,  that  when  spirit 
of  turpentine,  and  several  other  substances  which  are 
commonly  supposed  to  be  absorbed  by  the  skin,  were 
applied  to  it  in  a way  which  prevented  their  volatile 
parts  from  entering  the  lungs  by  respiration,  no  ab- 
sorption took  place.  But  when  they  inspired  air  im- 
pregnated with  exhalations  from  these  substances,  they 
perceived  satisfactory  proofs  that  the  exhalations  en- 
tered the  system.  From  these  facts  they  inferred  that 
when  those  articles  entered  the  body  by  absorption, 
they  were  taken  in  by  the  lungs,  and  not  by  the  exter- 
nal surface. 

On  the  other  hand,  the  two  gentlemen  last  mentioned, 
state  that  after  immersing  themselves  in  a bath  consist- 
ing of  a decoction  of  rhubarb,  of  madder,  or  of  turmeric, 
their  urine  became  tinged  with  these  substances.  They 
also  assert  that  the  colouring  matter  of  these  different 

I believe  that  M.  Seguin’s  Memoir  on  this  subject  was  read  to  the 
Academy  of  Sciences  a short  time  before  the  meetings  of  that  body 
were  suspended.  It  was  published  by  M.  Fourcroy,  in  La  Medicine 
Eclairee  par  les  Sciences  Physiques,  vol.  iii. — An  extract  from  M. 
Fourcroy’s  publication  may  be  seen  in  the  19th  chapter  of  the  first 
volume  of  Dr.  Currie’s  “ Medical  Reports  on  the  Effects  of  W ater,” 
&c.,  in  which  is  also  contained  a statement  of  the  Doctor’s  own  expe- 
riments and  reflections. 

VOL.  II. 


3.E 


402  Experiments  of  K.  Boerhaaite  and  f.  Hunter. 

ai  tides  is  not  volatile;  and,  therefore,  could  not  have 
entered  the  lungs  during  the  experiments.* 

The  statement  in  page  380,  from  Dr.  Soemmering,  that 
when  mercury  is  injected  backwards  in  the  absorbent 
vessels  which  originate  on  the  foot,  it  will  sometimes 
appear  in  small  globules  on  the  skin  of  the  foot,  has 
an  important  connexion  with  this  subject.! 


About  the  middle  of  the  last  century,  it  was  generally 
believed  by  anatomists,  that  absorption  was  performed 
by  the  veins.  This  doctrine  seemed  to  be  established 
by  the  experiments  of  Kaaw  Boerhaave,  which  are 
related,  with  many  other  interesting  statements,  in 
his  work  entitled  “ Perspiratio  Dicta  Hippocrati,”  &c., 
published  at  Leyden,  in  1738.  In  these  experiments  it 
appeared  to  the  author,  that  when  the  stomach  of  a. 
dog  was  emptied  of  its  contents,  and  filled  with  warm 
water,  immediately  after  death,  the  water  passed  into 
the  minute  ramifications  of  the  veins  of  the  stomach, 
and  from  them  to  the  vena  portarum,  and  ultimately 
to  the  heart,  in  large  quantities. 

This  account  appears  to  be  disproved  by  some  experi- 
ments of  the  late  John  Hunter,  made  about  twenty 
years  after,  and  published  in  the  Medical  Commentaries 
of  Dr.  William  Hunter,  Part  I. Mr.  Hunter’s  ex- 

* The  Thesis  of  Dr.  Rousseau  was  published  in  1800.  Those  of 
Drs.  Klapp  and  Daingerfield  in  1805.  Dr.  Mussey  published  in  the 
.Third  Supplement  to  the  Medical  and  Physical  Journal  of  Dr.  Barton, 
in  1809.  Dr.  Stewart  published  in  1810. — Additional  observations  by 
Drs.  Klapp,  Rousseau  and  Smith,  are  published  in  the  Philadelphia 
Medical  Museum,  Vol.  I.  new  series. 

f Since  the  publication  of  the  first  volume,  the  author  has  enjoyed 
the  advantage  of  consulting  a translation,  in  manuscript,  of  some  parts 
of  the  German  edition  of  Dr.  Soemmering’s  valuable  work  on  the 
Structure  of  the  Human  Body. 


403 


Experiments  of  Magendie  and  Delile. 

periments  have  been  considered  as  establishing  the 
fact,  that  absorption  (in  the  intestines  at  least)  is 
performed  exclusively  by  the  lacteals,  or  proper  ab- 
sorbent vessels,  and  not  at  all  by  the  veins.  Kaaw 
Boerhaave  is  of  course  supposed  to  have  been  mis- 
taken; and  Mascagni,  who  has  repeated  his  experi- 
ment, refers  the  appearance  of  water  in  the  veins  to 
transudation,  through  the  coats  of  the  intestines;  which 
he  has  observed  to  take  place  to  a great  degree. 

In  the  year  1809,  a memoir  v/as  presented  to  the  national 
institute  of  France  by  Messrs.  Magendie  and  Delile, 
which  contains  an  account  of  some  experiments  that 
have  an  important  relation  to  the  above  mentioned 
subject.* — The  authors  being  greatly  surprised  at  the 
rapidity  with  which  the  poison  of  Java,  See.  appeared  to 
enter  the  sanguiferous  system,  instituted  a series  of 
experiments  to  determine  whether  these  substances 
proceeded  to  that  system  by  the  circuitous  route  of 
the  absorbent  vessels,  or  by  the  shorter  course  of  the 
veins.  Two  of  their  experiments  are  especially  inte- 
resting. They  made  an  incision  through  the  parietes  of 
the  abdomen  of  a living  dog,  who  had  eaten  a large 
quantity  of  meat  some  hours  before  (that  his  lacteals 
might  be  visible  from  their  distention  with  chyle),  and, 
drawing  out  a portion  of  the  small  intestine,  they  ap- 
plied two  ligatures  to  it,  at  the  distance  of  five  inches 
from  each  other.  The  portion  ofintestine  between  these 
ligatures  was  then  separated  by  incision  from  the  rest 
of  the  intestinal  tube,  and  all  the  lacteals,  bloodvessels, 
&c.  which  passed  to  and  fromit,  were  divided, except  one 

* The  title  of  the  paper  is  a “Memoir  on  the  Organs  of  Absorption 
in  Mammiferous  Animals.”  A translation  of  it  was  published  in  the 
Medical  and  Philosophical  Register  of  New  York,  and  in  several  other 
periodical  works. 


404  Experiments  of  Magendie  and  Delile. 

artery  and  a vein.  A considerable  length  of  this  artery 
and  vein  were  detached  from  all  the  surrounding  parts, 
so  that  the  authors  supposed  these  vessels  to  form  the 
only  connexion  between  the  poriion  of  the  intestine  and 
the  rest  of  the  body.  Into  the  cavity  of  the  intestine, 
which  was  thus  circumstanced,  they  introduced  a small 
quantity  of  the  poison,  and,  to  their  astonishment,  it 
produced  its  fatal  effects  in  the  same  manner  it  would 
have  done  if  it  had  been  introduced  into  the  intestine 
while  all  its  connexions  with  the  body  were  entire. 
This  experiment,  they  assert,  was  repeated  several 
times,  without  any  difference  in  the  result. 

After  several  other  experiments,  they  finally  separated  the 
thigh  from  the  body  of  a living  dog  in  such  a manner 
that  the  crural  artery  and  vein  were  left  undivided. 
A quill  was  then  introduced  into  the  artery,  and  two 
ligatures  were  applied  to  fix  it  round  the  quill.  The 
artery  was  then  divided  between  the  ligatures.  The 
vein  was  managed  in  the  same  manner.  There  was, 
therefore,  no  communication  between  the  limb  and 
the  body,  except  by  the  blood  which  passed  through 
the  divided  vessels  and  the  quills.  The  poison  was 
then  introduced  under  the  skin  of  the  foot,  and  soon 
occasioned  the  death  of  the  animal:  its  deleterious 
effects  commencing  about  four  minutes  after  its  appli- 
cation to  the  foot.  This  experiment  appears  to  prove 
decidedly  that  the  blood  is  the  vehicle  by  which 
poison,  when  applied  to  the  extremities,  is  carried 
to  the  body;  although  it  may  not  determine  the  ques- 
tion whether  this  poison  was  taken  up  by  the  absorbents 
or  by  the  veins. 

Some  other  experiments  made  by  the  authors  gave  re- 
sults, which  are  very  difficult  indeed  to  explain.  They 
wished  to  know  if  the  blood  of  an  animal  thus  contami- 
nated, would  produce  similar  effects  upon  another  ani- 


Experiments  of  Magendie  and  D elite.  405 

mal;  and,  with  a view  to  ascertain  this  point,  they 
insinuated  a small  piece  of  wood,  covered  with  the 
poison,  into  the  thick  part  of  the  left  side  of  the  nose 
of  a dog.  Three  minutes  after  the  introduction  of  the 
poison,  they  transfused  blood  from  the  jug  ular  vein  of  the 
same  side,  into  one  of  the  veins  of  another  dog.  Abou' 
one  minute  after  the  commencement  of  the  transfu 
sion,  the  effects  of  the  poison  began  in  the  dog  to  which 
it  was  applied,  and  continued  until  his  death.  Transfu* 
sion  into  the  veins  of  the  other  dog  went  on  during 
the  whole  time,  and  he  received  a large  quantity  of  blood 
from  the  dying  dog,  without  producing  any  effect.— 
They  varied  this  experiment  in  the  following  manner. 
The  thigh  of  a dog  was  separated  from  the  body;  the  ar- 
tery and  the  vein  were  arranged  as  in  the  former  expe- 
riment; and  poison  was  introduced  into  the  foot.  Three 
minutes  after  the  introduction  of  the  poison,  the  blood 
of  the  crural  vein  was  passed  into  the  jugular  vein  of 
another  animal,  and  transfusion  was  continued  five 
minutes  without  producing  any  effect  upon  the  animal 
receiving  the  blood:  it  was  then  stopped,  and  the  crural 
vein  was  so  arranged  that  the  blood  flowed  from  it  into 
the  animal  to  which  it  belonged.  This  animal  very  soon 
exhibited  symptoms  of  the  operation  of  the  poison.* 
From  these  very  interesting  experiments  the  authors  in- 
fer that  “ foreign  matters  do  not  always  proceed  through 
the  Lymphatic  or  Absorbent  Vessels , when  they  enter  into 
the  Sanguiferous  system.” 

* An  account  of  these  experiments  was  published  by  M.  Magendie 
in  a pamphlet.  A statement  of  them  is  also  contained  in  the  report 
made  to  the  Institute  by  the  committee  to  whom  the  memoir  was 
referred,  which  is  published  in  the  Journal  de  Physique,  for  March- 
1813.  In  that  statement  this  last  mentioned  experiment  is  omitted. 


40.6  Report  of  the  Committee  of  the  Institute. 

This  memoir  was  referred  by  the  Institute  to  four  of  its 
members,  who  are  particularly  distinguished  by  their 
profound  knowledge  of  anatomy  and  physiology.  These 
gentlemen,  after  stating  their  belief  that  the  func- 
tions of  the  lymphatic  or  absorbent  system  have  been 
completely  ascertained  by  the  experiments  and  ob- 
servations of  Hunter,  Cruikshank,  Mascagni,  &c.,  say 
further,  that,  in  their  opinion,  the  above  mentioned  in- 
ference ought  to  be  a little  modified,  and  that  facts  are 
not  sufficiently  numerous,  or  applicable  to  the  point  in 
question,  to  justify  the  inference  that  foreign  matters 
do  not  always  proceed  through  the  Lymphatic  or  Ab- 
sorbent Vessels,  when  they  enter  the  Sanguiferous  system. 
But  they  also  add,  that,  as  the  author  is  still  engaged 
in  a series  of  experiments  on  the  subject,  they  will 
suspend  their  judgment  respecting  the  inferences  to 
be  deduced  from  the  present  statement. 


The  most  extensive  account  of  the  absorbent  system  is 
contained  in  the  £<  Historia  et  Ichnographia  Vasorum 
Lymphaticorum  Corporis  Humani”  of  Mascagni. — 
“ The  Anatomy  of  the  Absorbing  Vessels  of  the  Hu- 
man Body,  by  W.  Cruikshank;” — and  “ The  Descrip- 
tion of  the  Lymphatic  System,  by  Wm.  Hewson,”  (the 
second  volume  of  his  Experimental  Inquiries)-— are  also 
very  interesting  publications. 


SYSTEM  OF  ANATOMY 


APPENDIX. 


;'-U  ' - 


' - 


;:v- 

■ ; ' ’ - ’ - "• 


■ . • : 

■ 


APPENDIX. 


OF  THE  BLOOD. 


The  blood  of  a healthy  person  indicates  a tendency  to 
coagulate  very  soon  after  it  is  discharged  from  the  vessels 
which  naturally  contain  it,  although  it  is  perfectly  fluid  in 
those  vessels. 

If  it  remains  at  rest,  after  it  is  drawn  from  the  vessels, 
it  soon  coagulates  into  a solid  mass,  of  a soft  texture. 
From  this  solid  mass  a fluid  is  soon  observed  to  issue, 
which  first  appears  in  very  small  drops  on  almost  every 
part  of  the  surface.  These  drops  quickly  increase  and  run 
together,  and  in  a short  time  the  fluid  surrounds  the  solid 
mass,  and  exceeds  it  in  quantity. 

The  solid  part  which  thus  appears  upon  the  spontaneous 
separation  of  the  blood,  is  denominated  Crassamentum  or 
Cruor:  the  fluid  part  is  called  Serum. 

The  substance  which  contains  the  red  colour  of  the 
blood  remains  with  the  Crassamentum.  The  Serum , when 
it  separates  without  agitation,  is  free  from  the  red  colour. 

The  colouring  matter  may  be  separated  completely 
from  the  Crassamentum  by  washing  it  with  water. 

Vol.  II.  3 F 


410 


Appendix.— -Of  the  Blood. 

The  blood,  therefore,  consists  of  three  parts,  viz.  the 
Serum;  the  Substance  which  coagulates  spontaneously ; and 
the  Colouring  Matter. 

THE  SERUM 

Has  a considerable  degree  of  consistence,  although  it  is 
much  thinner  than  blood.  In  its  perfectly  natural  state,  it 
is  almost  transparent,  and  appears  to  be  very  lightly  ting- 
ed with  a greenish  yellow  colour;  but  it  is  very  often  im- 
pregnated with  a portion  of  bile,  which  is  probably  carried 
to  the  bloodvessels  by  the  absorbents.  It  contains  a large 
quantity  of  albumen,  or  matter  like  the  white  of  an  egg.  If 
heated  to  140°  of  Fahrenheit,  it  becomes  opake;  and  when 
the  heat  is  increased  to  156  or  160,  it  is  firmly  coagulated. 
It  is  also  coagulated  by  alcohol,  by  mineral  acids,  and  by 
rennet.*  It  is  proved  by  chemists,  that  it  contains  a small 
quantity  of  pure  soda.  It  therefore  changes  several  of 
the  blue  colours  of  vegetables  green.  It  is  also  found  to 
contain  a similar  quantity  of  the  muriate  and  the  phosphate 
of  soda,  and  the  phosphate  of  lime.  These  saline  substan- 
ces were  discovered  by  diluting  serum  with  water,  and 
exposing  the  mixture  to  heat,  by  which  the  albumen  was 
coagulated  into  flocculse:  these  flocculse  were  separated 
by  filtration:  the  liquor  was  then  diminished  by  evapora- 
tion, and  the  salts  obtained  from  it  by  crystallization. 

Serum  likewise  contains  a portion  of  sulphur  combined 
with  ammonia. 

When  it  is  exposed  to  a coagulating  heat,  a small  por- 
tion of  it  remains  fluid. 

This  fluid  portion  has  been  supposed  to  contain  a con- 

* See  Hewson,  Vol.  I.  p.  139. — 1 suspect  that  some  particular  ma 
nagement  is  necessary  in  the  use  of  rennet. 


411 


Appendix.-— Of  the  Blood. 

siderable  quantity  of  gelatine;  but  it  is  contended  by  Mr. 
Brande,*  that  Gelatine  does  not  exist  in  the  serum  of  the 
blood,  and  that  this  portion  consists  of  albumen  combined 
with  a proportion  of  alkali. 

It  is  also  asserted  by  Dr.  Bostock,f  one  of  the  latest 
writers  on  the  subject,  that  the  serosity  of  the  blood  (the 
term  applied  to  the  last  mentioned  fluid)  contains  no  ge- 
latine; but  that,  with  a minute  quantity  of  albumen,  it 
consists  of  a large  portion  of  an  animal  matter,  which 
is  different  either  from  gelatine  or  albumen,  being  unlike 
either  of  them,  in  its  chemical  qualities. 

THE  CRASSAMENTUM 

Is  rendered  very  different  in  its  appearance,  by  the  dif- 
ferent circumstances  in  which  it  may  coagulate. 

When  the  blood  remains  at  rest  immediately  after  it  is 
drawn,  the  crassamentum  which  forms  in  it  is  a concrete 
substance,  without  the  smallest  appearance  of  fibre  in  its 
composition.  If  the  blood  is  stirred  with  a rough  stick, 
while  it  is  flowing  from  an  animal,  a large  portion  of  it 
will  concrete  upon  the  stick,  in  a fibrous  form,  so  as  to 
resemble  a.  mass  of  entangled  thread,  some  of  the  red 
eolouring  matter  still  adhering  to  it. 

The  crassamentum,  in  either  of  these  forms,  may  be 
washed  perfectly  white;  the  red  colouring  matter  passing 
completely  away  with  the  water.  In  this  state  it  appears}: 

* In  his  Researches  on  the  Blood,  communicated  to  the  Royal  So- 
ciety of  London  in  1812,  and  republished  in  the  Eclectic  Repertory, 
for  April  1813. 

f See  his  Observations  on  the  Serum  of  the  Blood,  in  the  Medico- 
Chirurgical  Transactions,  Vol.  II.,  republished  in  the  Eclectic  Reper- 
tory, for  October  1813. 

f By  the  experiments  of  Mr.  Charles  Hatchett,  published  in  the 
London  Philosophical  Transactions  for  1800. 


412 


Appendix.*— -Of  the  Blood. 

to  have  all  the  chemical  properties  of  the  fibrous  matter 
of  muscular  flesh.  It  also  resembles  the  gluten  of  vegeta- 
bles, being  soft  and  elastic.  The  name  fibrin  is  now 
generally  applied  to  it. 

If  fibrin  is  washed  and  dried,  its  weight  is  very  small 
indeed  when  compared  with  that  of  the  blood  from  which 
it  has  been  obtained.  It  is,  therefore,  probable  that  a 
considerable  proportion  of  the  bulk  of  the  crassamentum, 
as  it  forms  spontaneously,  depends  upon  the  serum  which 
exists  in  it,  and  can  be  washed  away. 

The  spontaneous  coagulation  of  the  blood,  which  ap- 
pears to  depend  principally  upon  the  Fibrin , may  be  pre- 
vented by  the  addition  of  several  foreign  substances  to  the 
blood,  when  it  is  drawn.  It  is  subject  to  great  variations 
that  depend  upon  the  state  of  the  body  at  the  time  of 
bleeding;  and  in  some  conditions,  it  does  not  take  place 
at  all.* 

In  a majority  of  dead  subjects  the  blood  is  found  more 
or  less  coagulated  in  the  veins;  but  in  some  subjects  it  is 
found  without  coagulation.  It  is  asserted  that  it  does  not 
coagulate  in  subjects  who  have  died  suddenly,  in  conse- 
quence of  anger,  lightning,  or  a blow  on  the  stomach. 

THE  COLOURING  MATTER. 

When  the  bloodvessels  in  the  transparent  parts  of 
certain  living  animals  are  examined  with  magnifying 
glasses,  it  appears  that  the  red  colour  of  the  blood  is 
owing  to  bodies  of  a globular  form,  which  are  diffused 

* See  an  Inquiry  into  the  Properties  of  tire  Blood,  by  the  late  Win. 
Hewson:  and  Experiments  by  his  son,  T.  T.  Hewson,  in  the  Eclectic 
Repertory,  Jan.  1811. — See  also  a Treatise  on  the  Blood,  &c.  by  the 
late  J.  Huntei'. 


413 


Appendix . — Of  the  Blood . 

through  a transparent  fluid.  The  appearance  of  these 
bodies  has  been  examined,  with  great  attention,  by  many 
physiologists,  since  the  publication  of  Leuwenhoeck,  in  the 
London  Philosophical  Transactions.* 

Several  of  these  gentlemen  have  described  the  appear- 
ance of  the  blood  very  differently;  but  Haller,  Spalanzani 
and  J.  Hunter  agree  that  the  figure  of  the  red  particles  is 
globular,  f Hunter  observes  further,  that  the  red  globules 
do  not  run  into  each  other  as  two  globules  of  oil  would  do 
when  divided  by  water;  and  he  believes  that  they  cannot 
unite.  At  the  same  time  they  seem  not  to  have  the  pro- 
perties of  a solid:  for  when  circulating  in  the  vessels,  they 
assume  elliptical  forms,  adapting  themselves  to  the  size  of 
the  vessels.  They  also  excite  no  sensation  of  solidity 
when  touched. 

'*  Among  the  most  distinguished  of  these  observers  were  Father  de 
la  Torre,  Haller,  Hewson,  Fontana,  Spalanzani,  J.  Hunter,  Cavallo. 

Some  short  accounts  of  Leuwenhoeck’s  original  observations  on  the 
blood  are  to  be  found  in  the  Philosophical  Transactions  of  London,  for 
1664,  in  the  fasciculi  which  are  numbered  102  and  106.  A more  full 
description  is  contained  in  Boerhaave’s  Academical  Lectures  on  the 
Theory  of  Physic.  See  the  section  on  the  nature  of  the  blood. 

The  glasses  of  Father  de  la  Torre  were  transmitted  from  Naples  to 
the  Royal  Society  of  London  in  1765.  They  were  accompanied  by  a 
letter  from  Sir  F.  H.  E.  Stiles,  to  which  are  subjoined  some  observa- 
tions by  the  Rev.  Father  himself.  The  letter  and  the  observations  are 
published  in  the  55th  volume  of  the  transactions  of  that  society. 

In  the  year  1798,  Tiberius  Cavallo  published  an  Essay  on  the  Me- 
dicinal Properties  of  Factitious  Air,  with  an  appendix  on  the  Nature  of 
the  Blood;  in  which  is  contained  a further  account  of  the  glasses  of  De 
la  Torre. 

f I believe  that  this  is  also  the  opinion  of  Fontana. — In  J.  Hunter’s 
work  on  the  Blood  there  are  some  interesting  observations  on  micros- 
copical deceptions.  See  the  note,  commencing  in  page  39,  Bradford’s 
edition. 


414 


Appendix. — Of  the  Blood. 

They  appear  to  be  more  heavy  than  the  other  parts  of 
the  crassamentum:  for  in  healthy  blood  the  lower  part  of 
the  mass  contains  more  of  the  colouring  matter  than  the 
upper  part,  and  in  the  blood  of  persons  who  labour  under 
acute  local  inflammation,  they  often  subside  completely 
from  the  upper  part;  and  thus  occasion  what  is  called,  by 
Mr.  Hewson,  the  inflammatory  crust , or  size. 

It  has  been  observed  by  Mr.  Hewson,  and  also  by  Mr. 
Hunter,  that  the  globules  do  not  retain  their  form  in  every 
fluid.  They  are  said  to  be  dissolved  very  quickly  in  water, 
and  then  they  form  a fine  clear  red.  Several  of  the  neutral 
salts,  when  dissolved  in  water,  prevent  the  solution  of  the 
globules.  Mr.  Hunter  informs  us,  that  the  vitriolic  acid, 
when  greatly  diluted,  does  not  dissolve  them,  &c.  The 
muriatic  acid,  when  three  times  as  strong  as  vinegar, 
destroys  their  colour  without  dissolving  them,  although 
when  more  diluted,  it  dissolves  them. 

The  colour  of  the  blood  has,  for  a long  time,  been  sup- 
posed to  depend  upon  Iron.  About  the  middle  of  the  last 
century,  Vincentius  Menghini  published  in  the  Transac- 
tions of  the  Academy  of  Sciences  of  Bologna,  an  account  of 
experiments  which  contributed  to  establish  this  sentiment. 
In  this  account  he  stated,  that,  after  washing  the  colouring 
matter  from  the  crassamentum,  he  had  separated  it  from 
the  water  by  boiling;  in  which  case  it  either  rose  to  the 
surface  of  the  water,  or  subsided,  and  left  the  water 
clear.  After  drying,  with  a gentle  heat,  some  of  the 
colouring  matter  thus  separated,  and  then  repeatedly 
washing  it,  he  found  that  it  contained  a considerable 
quantity  of  iron,  which  was  attracted  by  the  magnet. 

After  exposing  a large  quantity  of  the  colouring  matter 
to  an  intense  heat,  he  found  in  it  a small  piece  of  iron,  of 


Appendix. —Of  the  Blood.  415 

a spherical  form,  but  hollow;  and  a powder  which  was 
attracted  by  the  magnet,  but  appeared  more  like  rust  of 
iron  than  iron  filings. 

He  believes  the  seat  of  this  iron  to  be  in  the  colouring 
matter  of  the  blood,  as  neither  the  serum  nor  fibrina 
appeared  to  contain  it. — According  to  his  calculation,  the 
blood  of  a healthy  man  contains  more  than  two  ounces  of 
iron. 

This  doctrine  of  Menghini  has  been  very  generally 
admitted;  and  several  chemists  of  the  first  character,  viz. 
Bucquet,  Fourcroy,  Vauquelin,  &c.  have  made  experi- 
ments to  ascertain  the  substances  with  which  the  iron  in 
the  blood  is  combined. 

But  within  a few  years,  doubts  have  been  expressed  on 
this  subject  by  several  physiologists,  and  especially  by 
Dr.  Wells  and  Mr.  Brande. 

The  first  of  these  gentlemen,  in  his  “ Observations  and 
Experiments  on  the  Colour  of  the  Blood f published  in  the 
London  Philosophical  Transactions  for  1797,  states  three 
reasons  for  rejecting  the  opinion  that  the  colour  of  the 
blood  is  derived  from  iron. 

1.  The  colour  of  blood  is  destroyed  by  a heat  less  than 
that  of  boiling  water:  whereas  no  colour  arising  from  a 
metal  is  destroyed  by  exposing  its  subject,  in  a close  ves- 
sel, to  such  a heat. 

2.  If  the  colour  from  a metal,  in  any  substance,  be 
destroyed  by  an  alkali,  it  may  be  restored  by  the  imme- 
diate addition  of  an  acid;  and  the  like  will  happen  by  the 
addition  of  a proper  quantity  of  an  alkali,  if  the  colour 
has  been  destroyed  by  an  acid.  The  colour  of  blood,  on 
the  contrary,  when  once  destroyed,  can  never  be  brought 
back,  either  by  an  acid  or  an  alkali. 


416 


Appendix.— Of  the  Blood. 

3.  If  iron  be  the  cause  of  the  red  colour  of  blood,  it 
must  exist  there  in  a saline  state;  since  the  red  matter 
is  soluble  in  water.  The  substances,  therefore,  which  de- 
tect the  smallest  quantity  of  iron  in  such  a state,  ought 
likewise  to  demonstrate  its  presence  in  blood;  but  upon 
adding  Prussian  alkali,  and  an  infusion  of  galls,  to  a very 
saturated  solution  of  the  red  matter,  he  could  not  observe 
“ in  the  former  case  the  slightest  blue  precipitate;  or  in 
the  latter  that  the  mixture  had  acquired  the  least  blue 
or  purple  tint.” 

Mr.  Brande,  in  a paper  entitled  “ Chemical  Researches 
on  the  Bloodf  &c.  communicated  to  the  Royal  Society  of 
London  in  1812,  relates  many  experiments  which  were 
made  on  the  colouring  matter  of  that  fluid,  with  acids, 
alkalies,  astringents,  &c.  &c.  From  these  experiments 
he  also  infers,  that  the  colouring  matter  of  the  blood  is 
perfectly  independent  of  iron. 

In  support  of  this  inference,  he  adds,  that  the  Armenian 
dyers,  in  the  preparation  of  their  finest  and  most  durable 
red  colours,  use  blood  in  addition  to  madder,  in  order  to 
insure  the  permanency  of  these  colours.  As  the  compounds 
of  iron  convert  the  colour  of  madder  to  gray  and  black, 
the  production  of  a bright  colour,  by  the  addition  of 
blood  to  madder,  he  regards  as  a proof,  that  iron  is  not 
the  colouring  matter  of  blood. 

Many  estimates  have  been  made  of  the  quantity  of 
blood  in  the  human  body;  but  some  of  the  best  informed 
physiologists  have  regarded  them  as  fallacious. 


Appendix.*— Structure  of  Glands. 


417 


STRUCTURE  OF  GLANDS. 

Any  original  structure  that  discharges  from  the  blood- 
vessels a fluid  different  from  those  which  they  naturally 
contain,  may  be  considered  as  glandular.  The  function  or 
process  by  which  such  fluids  are  derived  from  the  blood- 
vessels is  called  secretion. 

A structure  of  this  kind  seems  to  exist  in  very  different 
situations:  for  it  is  distinctly  circumscribed  in  many  of 
those  bodies  commonly  denominated  glands,  which  are 
of  a very  precise  form;  and  it  is  also  diffused  on  some 
very  extensive  surfaces.  The  gastric  liquor,  a most  im- 
portant secretion,  is  probably  discharged  from  vessels 
which  open,  like  exhalents,  on  the  internal  surface  of 
the  stomach;  and  not  from  any  circumscribed  bodies, 
which  are  generally  denominated  glands. 

The  name  of  gland  is  theoretically  applied  to  several 
bodies  which  cannot  be  proved  to  secrete  anv  fluid  what- 
ever; and  also  to  those  bodies  connected  with  the  absorbent 
vessels,  which  are  called  the  Lymphatic  Glmids;  but  it  is 
most  commonly  appropriated  to  those  organs  which  dis- 
charge a fluid  different  from  the  blood. 

The  structure  by  which  mucus  is  secreted  in  some 
places,  appears  to  be  very  simple.  Thus  in  theTSchneiderian 
membrane  and  the  urethra,  there  are  small  ducts  from 
four  to  six  lines  in  length,  and  equal  in  diameter  to  a 
bristle,  which  appear  to  be  formed  of  the  membrane  on 
which  they  open.  From  these  ducts  mucus  issues  to  cover 
the  surfaces  of  these  membranes.  In  many  instances  there 
is  no  substance  resembling  that  of  the  circumscribed 
glandular  bodies,  connected  with  these  ducts;  but  the 
secreted  fluid  seems  to  be  discharged  into  the  ducts 
Vol.  II.  3 G 


418  Appendix. — Structure  of  Glands. 

from  the  small  vessels  on  their  surfaces. — The  ducts  of 
this  nature  in  the  urethra  are  denominated  Lacunae. 

In  some  other  parts  of  the  body,  the  cavities  into  which 
mucus  is  discharged  are  somewhat  different,  both  in 
form  and  size,  from  those  above  mentioned,  and  are 
called  Follicles.  These  cavities  are  surrounded  with  more 
or  less  of  a pulpy  vascular  substance,  which  has  been 
considered  as  glandular,  and  essential  to  the  mucous 
secretion. 

The  circumscribed  bodies,  which  are  commonly  called 
glands,  differ  in  their  internal  appearance  and  texture, 
from  the  other  parts  of  animals.  The  substance  of  whicl^ 
they  consist  differs  very  much  in  the  different  glands; 
and  thus  renders  the  liver,  kidneys,  salivary  glands, 
mammae,  &c.,  very  different  from  each  other.  Some 
glands,  as  the  salivary,  &c.,  are  composed  of  several 
series  of  lobuli  that  successively  diminish.  The  smallest 
of  these  are  denominated  Acini.  Each  of  them  is  connect- 
ed by  a small  artery  and  vein,  to  the  large  bloodvessels  of 
the  gland;  and  also  sends  a branch  to  join  the  excretory 
duct.  These  Acini  are  therefore  connected  to  each  other, 
by  the  bloodvessels  and  excretory  duct  of  the  gland,  and 
also  by  the  cellular  membrane,  which  covers  them  exter- 
nally, and  occasions  them  to  adhere  to  each  other  where 
they  are  in  contact.  In  consequence  of  this  structure, 
these  glands  have  a granulated  appearance. 

The  liver,  when  incised  with  a sharp  instrument,  ap- 
pears differently;  but  when  broken  into  pieces,  it  seems  to 
consist  of  small  acini.  Some  other  glands,  as  the  Prostate , 
appear  to  be  uniform  in  their  texture,  and  have  none  of 
this  granulated  appearance; 


Appendix. • — Structure  of  Glands.  419 

The  structure  of  glands  has  long  been  an  interesting 
object  of  anatomical  inquiry,  and  was  investigated  with 
great  assiduity  by  those  eminent  anatomists,  Malpighi 
and  Ruysch. 

Malpighi,  as  was  formerly  observed,  used  ink  and  other- 
coloured  fluids  in  his  injections.  He  was  also  very  skilful 
in  the  use  of  microscopes,  and  took  great  pains  in  mace- 
rating and  preparing  the  subjects  of  his  inquiries.  Ruysch, 
on  the  other  hand,  used  a ceraceous  injection,  and  was  most 
eminently  successful  in  filling  very  small  vessels  with  it. 
Malpighi  believed  that  there  were  follicles  or  cavities  in 
glandular  bodies,  which  existed  between  the  extremities 
of  the  arteries  and  the  commencement  of  the  excretory 
ducts  of  those  bodies,  and  that  in  these  cavities  the  se- 
creted fluids  underwent  a change. — Ruysch  contended, 
that  the  arteries  of  glands  were  continued  into  excretory 
ducts  without  the  intervention  of  any  cavity  or  follicle; 
that  the  small  bodies,  which  had  been  supposed  to  con- 
tain follicles  or  criptae,  were  formed  by  convolutions  of 
vessels,  and  that  the  change  of  the  fluid,  or  the  process  of 
secretion,  is  produced  by  the  minute  ramifications  of  the 
artery. 

A very  interesting  account  of  this  subject  is  contained  in 
two  celebrated  letters,  which  passed  between  Boerhaave 
and  Ruysch  in  the  year  1721,  and  are  published  at  the 
end  of  the  fourth  volume  of  the  works  of  Ruysch. 

The  opinion  of  Ruysch  has  been  most  generally  adopted 
by  anatomists,  and  has  derived  support  and  confirmation 
from  several  anatomists  since  his  time. — The  late  Mr. 
Hewson  declared  his  conviction  that  the  small  globular 
bodies  which  are  scattered  through  the  kidneys,  and  were 
supposed  to  be  follicles  or  criptae,  are  merely  convoluted 


420  Appendix. — Structure  of  Glands. 

arteries.  He  also  asserted,  that  the  acini  which  appeared 
in  the  mammae  as  large  as  the  heads  of  pins,  when  the 
excretory  ducts  of  that  gland  were  injected  with  vermilion 
and  painters’  size,  proved  to  be  the  minute  ramifications 
of  the  excretory  duct,  which  divided  very  suddenly  into 
branches  so  small,  that  they  could  not  readily  be  seen  by 
the  naked  eye.* 

Notwithstanding  these  reasons  for  supposing  that  the 
excretory  ducts  of  glands  were  derived  simply  from  the 
arteries  of  those  bodies,  it  is  said  that  the  late  Dr.  W. 
Hunter  used  to  declare  his  belief,  that  there  was  a part  in 
glands  which  was  not  injected,  in  his  preparations;  and  to 
say  further,  that  he  believed  his  preparations  were  injected 
as  minutely  as  those  of  Ruysch. 

All  of  these  opinions  have  been  strenuously  controvert- 
ed by  the  Italian  anatomist,  Mascagni,  who  believes  that 
the  arteries  terminate  only  in  veins;  and  of  course  that 
they  neither  form  exhalent  vessels,  nor  communicate 
with  the  excretory  ducts  of  glands.  His  idea  of  the 
structure  of  glands  is  different  from  those  either  of 
Malpighi  or  of  Ruysch.  He  supposes  that  glands  contain 
a great  number  of  minute  cells;  that  the  arteries,  veins, 
and  absorbent  vessels  are  spread  upon  the  surfaces  of 
these  cells,  in  great  numbers,  and  very  irregularly.  From 
these  cells  very  small  canals  originate,  which  unite  to 
form  the  small  branches  of  the  excretory  ducts.  Accord- 
ing to  his  idea,  the  secreted  fluid  is  discharged  through 
pores  or  orifices  of  the  bloodvessels,  into  the  cells,  and 
proceeds  from  them,  through  the  canals,  into  the  branches 
of  the  excretory  ducts.  Absorbent  vessels,  in  great  num- 
bers, originate  from  these  cells. 


* See  Experimental  Inquiries,  Vol.  ii.  p.  178. 


Appendix. — Structure  of  Glands.  421 

In  his  great  work  on  the  absorbent  system,  when  treat- 
ing on  the  termination  of  arteries  and  the  commencement 
of  veins,  (Part  I.  Section  2.)  he  asserts,  that  if  the  kidneys 
are  successfully  injected  with  size,  coloured  with  vermi- 
lion, and  then  laid  open  by  a section  with  a razor,  it  will 
be  found  that  the  size  without  the  colour  has  passed  into 
"cells,  which  are  very  numerous;  that  the  arteries  and  veins 
are  ramified  most  minutely  on  the  surfaces  of  these  cells, 
and  that  the  tubuli  uriniferi,  as  well  as  the  absorbent  ves- 
sels, originate  from  them. 

He  supposed  that  a considerable  portion  of  the  fluid 
thus  passing  off  from  the  bloodvessels,  is  commonly  taken 
up  by  the  absorbent  vessels  of  the  kidneys:  for  in  two 
cases  in  which  he  found  the  absorbent  vessels  obstructed, 
a diabetes  existed,  which  he  considered  as  the  effect  of 
the  inactivity  of  the  absorbents.  He  asserts,  that  in  the 
liver,  pancreas,  mammae,  and  also  in  the  salivary  and 
lachrymal  glands,  the  minute  arteries  and  veins  are  also 
distributed  upon  the  surfaces  of  cells;  and  that  very  small 
canals  arise  from  these  cells,  and  unite  to  form  the  small 
branches  of  the  excretory  ducts. 

This  great  anatomist  appears  to  have  been  much  occu- 
pied with  microscopical  observations,  and  has  gone  largely 
into  the  discussion  of  this  subject.* 

* The  late  Dr.  W.  Hunter,  in  his  Medical  Commentaries,  (p.  40,) 
avowed  his  belief,  that  the  fluids,  which  appear  occasionally  in  the  vari- 
ous cavities  of  the  body,  transude  through  the  coats  of  the  bloodvessels. 
Mr.  Hewson  (Experimental  Inquiries,  Vol.  II  Chap.  7 ) suggested 
several  reasons  for  dissenting  from  this  opinion;  but  Mascagni  has 
endeavoured  to  support  it. — See  a long  note  to  the  above  mentioned 
section  of  his  work,  page  74. 


422  Appendix.— Structure  of  Glands. 

It  must,  however,  be  acknowledged,  that  no  information 
which  has  as  yet  been  obtained  respecting-  the  structure 
of  glands,  enables  us  to  explain  their  wonderful  effect 
upon  the  fluids  which  pass  through  them.  It  remains 
yet  to  be  ascertained  why  one  structure  forms  saliva 
and  another  bile;  or  why  so  much  apparatus  should  be 
necessary  for  the  secretion  of  milk,  when  adipose  matter 
appears  to  be  produced  by  the  mere  membrane  in  which 
it  is  contained. 

Dr.  Berzelius,  professor  of  chemistry  at  Stockholm,  in  a 
late  work  on  animal  chemistry,  asserts,  that  if  all  the 
nerves  going  to  a secretory  organ  are  divided,  secretion 
will  cease,  notwithstanding  the  continued  circulation 
of  the  blood.  From  this,  he  thinks,  that  secretions  de- 
pend upon  the  influence  of  nerves,  although  he  cannot 
explain  their  effect. 

Mr.  Home,  after  relating  some  experiments  upon  blood 
and  serum,  made  with  the  Voltaic  Battery,  proposes 
the  following  questions,  among  others:  Whether  a 
weaker  power  of  electricity  than  any  which  can  be  kept 
up  by  art,  may  be  capable  of  separa  ng  from  the  blood 
the  different  parts  of  which  it  is  comp  sed;  and  forming 
new  combinations  of  the  parts  so  separated? — Whether 
the  structure  of  the  nerves  may  enable  them  to  possess 
a low  electrical  power,  which  can  be  employed  for  that 
purpose?  fee. 

See  the  London  Philosophical  Transactions,  for 
1809,  Part  II.* 

* Mr.  Wollaston  has  also  published  a small  paper  on  this  subject,  so 
the  Philosophical  Magazine,  Vol.  33. 


GLOSSARY,* 


EXHIBITING  THE  DERIVATION  OF  CERTAIN  ANATOMICAL 
TERMS. 


A. 

Acetabulum.  The  cavity  which  receives  the  head  of 
the  thigh-bone;  from  acetum  vinegar:  so  called,  because  it 
represents  the  acetabulum  or  saucer  of  the  ancients,  in 
which  vinegar  was  held  for  the  use  of  the  table. 

Acini.  From  acinus  a grape. 

Acromion.  A process  of  the  scapula;  from  eeKfo?  extremity, 
and  apos  the  shoulder. 

Anastomosis.  The  communication  of  vessels  with  one  another; 
from  mx  through,  and  c-opec  a mouth. 

Anatomy.  The  dissection  of  the  human  body;  from  «»«,  and 
upvw  to  dissect. 

Anconeus.  A muscle;  so  called  from  «y«*>y  the  elbow. 

Aorta.  Aaprn;  from  air,  and  to  keep. 

Aponeurosis.  A tendinous  expansion;  from  sent,  and  vtvpov  a 
nerve;  from  an  erroneous  supposition  of  the  ancients,  that 
it  was  formed  by  an  expansion  of  nerve. 

Apophysis.  A process  of  a bone;  from  to  proceed  from. 

A synonyme  of  process. 

Arachnoides.  A net-like  membrane;  from  »fx%vn  a spider,  and 
nSW  likeness. 


By  Dr  Hooper. 


424 


GLOSSARY. 


Artery.  From  «ug  air,  and  r»ps<y  to  keep;  because  the  ancients 
supposed  that  air  only  was  contained  in  them. 

Arthrodia.  A species  of  connexion  of  bones;  from  cefOptu  to 
articulate. 

Arytanoides.  The  name  of  two  cartilages  of  the  larynx;  also 
applied  to  some  muscles  of  the  larynx;  from  ciyvrctivx  a fun- 
nel, and  a shape. 

Astragalus.  A bone  of  the  tarsus;  so  called  from  its  resem- 
blance to  a die  used  in  ancient  games,  from  «?-p*y<*Aos  a 
cockal  or  die. 

Atlas.  The  first  vertebra  of  the  neck;  so  called,  because  it  sus- 
tains the  head:  from  the  fable  of  Atlas  being  supposed  to 
have  supported  the  world;  or  from  arXcia  to  sustain,  because 
it  sustains  the  head. 

Azygos.  A term  applied  to  parts  without  a fellow,  from 
priv.  and  tyyo;  a yoke,  because  it  has  no  fellow. 

B. 

Bursa.  A bag;  from  /3up«r«:  generally  applied  to  the  bursae 
muscosae. 

C. 

Cancel/i.  Lattice  work;  generally  applied  to  the  recticular 
substance  in  bones. 

Cardia.  The  superior  opening  of  the  stomach;  from  x-uftia,  the 
heart. 

Garotid.  The  name  of  some  arteries  of  the  neck  and  head; 
from  xcipoa  to  cause  to  sleep;  for,  if  tied  with  a ligature,  the 
animal  was  said  to  be  affected  with  coma.  ■- 

Carfius.  Kapsros;  the  wrist. 

Clavicma.  The  clavicle  or  collar-bone,  a diminutive  of  clavis  a 
key;  so  called  from  its  resemblance  to  an  ancient  key. 

Ciinoid.  Four  processes  of  the  sella  turcica  of  the  ethmoid  bone 
are  so  called,  from  xXm  a bed,  and  likeness;  from  their 
supposed  resemblance  to  a couch. 


GLOSSARY.  425 

Clttoris.  A part  of  the  female  pudenda,  enclosed  by  the  labia 
majora;  from  xXua  to  enclose  or  hide. 

Colon.  The  first  of  the  large  intestines;  from  xuXov,  quasi  xoiXov, 
from  xaiXog  hollow. 

Coracoid.  From  xopctZ,  a crow,  and  tile;  resemblance;  shaped 
like  the  beak  of  a crow. 

Coronary.  From  corona  a crown.  The  vessels  of  the  heart, 
stomach,  &c.  are  so  called  because  they  surround  the  parts 
in  the  manner  of  a crown. 

Cotyloid.  From  xorvM  the  name  of  an  old  measure,  and  ulos 
resemblance;  resembling  the  kotule. 

Cranium.  The  skull;  x^xviov,  quasi  xx^xmv,  from  x»%x  the 
head. 

Cremaster . A muscle  so  called;  from  x^xa  to  suspend,  be- 
cause it  suspends  the  testicle. 

Cribriform.  From  cribrum  a sieve,  it  being  perforated  like  a 
sieve. 

Cricoid.  Annular,  round,  like  a ring;  from  x^ixog  a ring,  and 
ulos  likeness. 

Cuboides.  A bone  of  the  foot;  from  xvZos  a cube,  and  tilo;  like- 
ness; because  it  resembles  a cube. 

Cuneiform.  Some  bones  are  so  called;  from  cuneus  a wedge, 
and  forma  likeness;  being  shaped  like  a wedge. 

D. 

Deltoid.  A muscle  resembling  the  Greek  letter  A;  from  A, 
and  silos  resemblance. 

Diaphragm.  The  muscle  which  separates  the  thorax  from  the 
abdomen;  from  lix<p^xrla  to  divide. 

Diarthrosis.  A movable  connexion  of  bones;  from  to 

articulate. 

Digastric.  From  twice,  and  yxng  a belly;  having  two 
bellies. 

Difiloe.  The  spongy  substance  between  the  two  tables  of  the 
skull;  from  JisrAaw  to  double. 

Vol.  II.  3 H 


GLOSSARY. 


426 

Duodenum.  The  first  portion  of  the  small  intestines;  so  called 
because  the  ancients  supposed  that  it  did  not  exceed  the 
breadth  of  twelve  fingers;  from  duodenus , consisting  of 
twelve. 

Dura  Mater.  The  outermost  membrane  of  the  brain;  called 
dura,  because  it  is  much  harder  than  the  other  membranes, 
and  mater,  from  the  idea  of  the  ancients  that  it  was  the 
source  of  all  the  other  membranes. 

E. 

Embryo.  The  child  in  the  womb  is  so  called  before  the  fifth 
month,  after  which  it  is  termed  foetus;  from  eft&pva  to  bud 
forth. 

Enarthrosis.  An  articulation  of  bones;  from  sv  in,  and  a 

joint  or  articulation. 

Enteric.  Belonging  to  the  intestines;  from  tvrsgov  an  entrail  or 
intestine. 

Epidermis.  The  scarf  or  outermost  skin;  from  ivt  upon,  and 
hytis  the  skin. 

Epididymis.  The  small  oblong  body  which  lies  above  the  tes- 
ticles; from  mi  upon,  and  a testicle. 

Epigastric.  The  superior  part  of  the  abdomen;  from  upon, 
and  y«vjjg  the  stomach. 

Epiglottis.  A cartilage  of  the  larynx  so  called;  from  im  upon, 
and  yXarUs  the  aperture  of  the  larynx,  being  situated  upon 
the  glottis. 

Epiphysis.  A portion  of  bone  growing  upon  another  bone, 
but  separated  from  it  by  a cartilage:  from  ini  upon,  and  <$vu 
to  grow. 

Epiploon.  The  membranous  viscus  of  the  abdomen,  which 
covers  the  intestines,  and  hangs  to  the  bottom  of  the  stomach; 
from  o swim  upon. 

Ethmoid.  From  sfyeos  a sieve,  and  e<Sa5  resemblance;  being  per- 
forated like  a sieve. 


GLOSSARY. 


427 


F. 

Fascia.  An  expansion,  enclosing  other  parts,  like  a band; 
from  fastis  a bundle. 

Falciform.  Shaped  like  a scythe;  from  falx  a scythe. 
Fasciculus.  A little  bundle,  dim.  of fastis  a bundle. 

Fauces.  The  plural  of  faux,  the  top  of  the  throat. 


G. 

Ganglion.  Tetf-yXian,  a knot  in  the  course  of  a nerve. 

Gastrocnemius.  The  muscle  which  forms  the  thick  of  the  leg; 
from  y a belly,  and  the  leg. 

Geriio.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  chin,  as  genio-glossus — genio- 
hyoideus,  &c.;  from  ys mot  the  chin. 

Ginglymus.  An  articulation;  from  yifyAy^s;  a hinge. 

Glenoid  cavity.  From  yA»j»u  a cavity,  and  utos  resemblance. 

Gfosso.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  tongue;  as  glosso-pharyngeus — - 
glosso-staphilinus,  &c.;  from  y^aa-<rx  the  tongue. 

Glottis.  The  superior  opening  of  the  larynx  at  the  bottom  of 
the  tongue;  from  yXarlct  the  tongue. 

Glutaus.  The  name  of  a muscle;  from  yAsro?  the  buttocks. 

Gomfihosis.  Toy.(puiris,  a species  of  immovable  connexion  of 
bones;  from  ya^i pos  a nail,  because  one  bone  is  fixed  in 
another  bone  like  a nail  in  a board. 

H. 

Helix.  The  outward  circle  of  the  ear;  from  uhu  to  turn  about. 

Hefiar.  The  liver.  an  abdominal  viscus. 

Hyaloid.  From  glass,  and  likeness;  the  capsule  of  the 
vitreous  humour  of  the  eye  is  so  called,  from  its  transparent 
and  glassy  appearance. 

Hymen.  The  membrane  situated  at  the  entrance  of  the  virgin 
vagina;  from  ipnv  Hymen,  the  god  of  marriage. 


428 


GLOSSARY. 


Hyoides.  A bone  of  the  tongue,  so  called  from  its  resemblance 
to  the  Greek  u;  from  u,  and  resemblance. 

Hyfiochondrium.  That  part  of  the  body  which  lies  under  the 
cartilages  of  the  spurious  ribs;  from  viro  under,  and  £«v&jj«s 
a cartilage. 

Hypogastric.  The  lower  region  of  the  fore  part  of  the  abdomen; 
from  lira  under,  and  the  stomach. 

I. 

Ileon.  A portion  of  the  small  intestines;  from  uMt>  to  turn; 
being  always  convoluted. 

Ischium.  The  part  of  the  os  innominatum  upon  which  we  sit; 
from  urftva  to  sustain. 

L. 

Lacuna.  The  excretory  duct  of  the  glands  of  the  urethra  and 
vagina;  from  lacus  a channel. 

Lambdoidal  suture.  So  called  because  it  is  shaped  like  the 
letter  a;  from  a,  and  s ties  resemblance. 

Larynx.  The  superior  part  of  the  windpipe;  a cc(vy%  the  larynx. 

M. 

Masseter.  A muscle  of  the  face,  which  assists  in  the  action  of 
chewing;  from  poi<r<r«.op.ca  to  chew. 

Mastoid.  From  [taros  a breast,  and  i$os  likeness;  shaped  like 
a nipple  or  breast. 

Mediastinum.  The  production  of  the  pleura,  which  divides  the 
thorax  into  two  cavities;  from  medium  the  middle,  quasi  in 
medio  stare. 

Mesentery.  The  membranes  to  which  the  intestines  are  attach- 
ed; from  [tiros  the  middle,  and  ipnpov  an  intestine,  because  it 
is  in  the  middle  of  the  intestines. 

Mesocolon.  That  part  of  the  mesentery  in  the  middle  of  the 
colon;  from  (tiros  the  middle,  and  koMp  the  colon. 


I 


GLOSSARY.  429 

Metacarpus.  That  part  of  the  hand  between  the  carpus  and 
fingers;  from  ptrcc  after,  and  xctpiro s the  wrist. 

Metatarsus,  That  part  of  the  foot  between  the  tarsus  and  toes; 
from  fitrx  after,  and  T«ep<roj  the  tarsus. 

Mylo.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  near  the  grinders,  as  mylo-hyoideus , &c.; 
from  piuA/)  a grinder  tooth. 

O. 

Odontoid.  Tooth-like;  from  a tooth,  and  itHog  resemblance. 

CE sophagus.  The  canal  leading  from  the  pharynx  to  the  sto- 
mach; from  oiv  to  carry,  and  tpxyu  to  eat;  because  it  carries 
the  food  into  the  stomach. 

Olecranon.  The  elbow,  or  head  of  the  ulna;  from  atev*  the  cu- 
bit, and  xpctvov  the  head. 

Omentum.  An  abdominal  viscus;  so  called  from  omen  a guess; 
because  the  soothsayers  prophesied  from  the  inspection  of 
this  part. 

Omo.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  scapula,  as  omo-hyoideus , &c.  from 
upas  the  shoulder. 

Omoplata.  The  scapula  or  shoulder-blade;  from  apo;  the  shoul- 
der, and  ztXxtv;  broad. 

Osteology.  The  doctrine  of  the  bones;  from  octov  a bone,  and 
x*yes  a discourse. 

P. 

Pancreas.  A viscus  of  the  abdomen;  so  called  from  its  fleshy 
consistence;  from  all,  and  *psaS  flesh. 

Parenchyma.  The  substance  of  some  of  the  viscera  was  so 
called,  from  ■srxfiyxva  to  pour  through. 

Parotid  Gland;  from  ar*p«  near,  and  cv;  the  ear;  because  it  is 
situated  near  the  ear. 

Pelvis.  A bony  cavity  shaped  like  a bason;  from  a bason. 

Pericardium.  The  membrane  which  surrounds  the  heart;  from 
■srip  around,  and  Kxfttot  the  heart. 


430 


GLOSSARY. 


Pericranium.  The  membrane  which  covers  the  bones  of  the 
skull;  from  irt ft  around,  and  Kfctvuv  the  cranium  or  head. 

Periosteum.  The  membrane  which  surrounds  the  bones;  from 
i repi  around,  and  oreov  a bone. 

Peristaltic  motion  of  the  intestines;  from  arsfxs-eA Xa,  to  con- 
tract. 

Peritoneum.  The  membrane  lining  the  abdomen,  and  covering 
its  viscera;  from  mpiruva  to  extend  around. 

Phalanx.  The  bones  of  the  fingers  and  toes  are  called  phalanxes, 
from  their  regular  situation,  like  a <pxX»y g,  or  arrangement 
of  soldiers. 

Pharynx.  A membranous  bag  at  the  end  of  the  mouth;  onto  re 
cpifmt.  because  it  conveys  the  food  into  the  stomach. 

Phrenic  or  diaphragmatic  nerve.  Qptvts  the  diaphragm;  from 
<ppw>  the  mind,  because  the  ancients  supposed  it  to  be  the 
seat  of  the  mind. 

Pia  Mater.  The  innermost  membrane  of  the  brain;  so  called 
because  it  embraces  the  brain  as  a careful  mother  folds  her 
child. 

Pleura.  The  membrane  lining  the  thorax;  zrtevpa,  the  side. 

Plexus.  A kind  of  net-work  of  vessels  or  nerves;  from  plccto 
to  weave  together. 

Psoas.  A muscle  so  called;  from  Tpoa  the  loin,  being  situated 
in  the  loins. 

Pterygoid  process.  From  -zfhpv | a pen  or  wing,  and  u&s  liker 
ness;  so  called  from  its  likeness  to  a pen  or  wing. 

Pylorus.  The  lower  orifice  of  the  stomach,  which  opens  into 
the  intestines;  from  zrv^oa  to  guard  an  entrance,  because  it 
guards  as  it  were  the  entrance  of  the  bowels. 

R.» 

Raphe.  A suture;  from  pW la  to  sewT. 

Renes.  The  kidneys,  ano  ns  j>uv,  because  through  them  the  urine 
flows. 

Retina.  The  net-like  expansion  of  the  optic  nerve,  on  the  inner 
surface  of  the  eye;  from  rete  a net. 


GLOSSARY. 


431 


Rhomboides.  A muscle  so  called  from  its  shape;  from  papaSte 
a geometrical  figure,  whose  sides  are  equal  but  not  right- 
angled,  and  litlo 5 a likeness. 

Rotula.  The  knee-pan;  a dim.  of  rota  a wheel,  from  its  shape. 

S. 

Sacrum.  A bone  so  called;  from  saccr  sacred,  because  it  was 
once  offered  in  sacrifices. 

Salvatella.  A vein  of  the  foot,  so  called  because  it  was  thought 
that  opening  it  preserved  health,  and  cured  melancholy;  from 
salvo  to  preserve. 

Sanguis.  The  blood;  yvux.,  because  it  preserves  the 

body. 

Sar tortus.  A muscle  so  called,  because  tailors  cross  their  legs 
with  it;  from  sartor  a tailor. 

Scafiha.  The  depression  of  the  outer  ear  before  the  anti-helix; 
from  <rx.ct(pvi  a little  boat  or  skiff. 

Scaphoides.  A bone  of  the  carpus,  so  called  from  its  resem 
blance  to  a skiff;  from  <rxt*<pri  a skiff,  and  % likeness. 

Sclerotic.  A term  applied  to  the  outermost  or  hardest  membrane 
of  the  eye;  from  mtMfoa  'o  make  hard. 

Sesamoid  bones.  From  e-ns -«pesi  a grain,  and  sfSas  a likeness;  from 
their  resemblance  to  the  semen  sesami. 

Sig?noid.  Parts  are  so  called  from  their  resemblance  to  the 
letter  2;  from  2,  the  letter  Sigma,  and  s<Sa ? likeness. 

Sphenoid.  From  c-Qw  a wedge,  and  likeness;  shaped  like 
a wedge. 

Sphincter.  The  name  of  several  muscles  whose  office  is  to  shut 
up  the  aperture  around  which  they  are  placed;  from  <nf>fyya 
to  shut  up. 

Splanchnic.  From  owAaeyjci'a,  an  entrail. 

Symphysis.  A connexion  of  bones;  from  a-vutyvai  to  grow  to- 
gether. 

Synarthrosis.  A connexion  of  bones;  from  crw  with,  and  *pfyos 
a joint. 


432 


GLOSSARY. 


Synchondrosis.  A species  of  union  of  bones  by  means  of  carti- 
lage; from  o-w  with,  and  a cartilage. 

Synneurosis.  A species  of  connexion  of  bones  by  means  of 
membrane;  from  <rvv  with,  and  1% vp«»  a nerve;  because  mem- 
branes, ligaments,  and  tendons,  were  by  the  ancients  con- 
sidered as  nerves. 

Syssarcosis.  A species  of  connexion  of  bones  by  means  of 
muscle;  from  <ry»  with,  and  <r«pg  flesh. 

Systole.  The  contractile  motion  of  the  heart  and  arteries;  from 
o-vrsAA*)  to  contract. 

T. 

Tendon.  From  tata  to  extend. 

Thorax.  ©<ypag.  The  breast  or  chest. 

Thyroid.  From  S'vpeej  a shield,  and  likeness;  shaped  like  a 
shield. 

Trachea.  The  windpipe,  so  called  from  its  roughness;  from 
TpctX,vi  rough. 

Trochanter.  A process  of  the  thigh-bone,  so  called  from  rpt%t>s 
a wheel. 

U. 

Ulna.  A name  for  the  cubit;  from  aXm  the  cubit. 

Ureter.  The  canal  which  conveys  the  urine  from  the  kidney  to 
the  bladder;  from  span  urine. 

Urethra.  The  passage  through  which  the  urine  passes  from 
the  bladder;  from  apov  the  urine. 

Uvea.  The  posterior  lamina  of  the  iris,  so  called  because  in 
many  animals  it  is  of  the  colour  of  unripe  grapes;  from  uva 
an  unripe  grape. 

Uvula.  The  conical  substance  which  hangs  down  from  the 
middle  of  the  soft  palate;  so  called  from  its  resemblance  to 
a grape.  A dim.  of  uva  a grape. 


GLOSSARY. 


433 


V. 

Valves.  From  valves  folding  doors. 

Vertebra.  The  bones  of  the  spine  are  so  called;  from  verto  to 
turn. 

X. 

Xiphoid.  So  called  from  the  resemblance  to  a sword;  from 
'a  sword,  and  trfos  likeness. 

Z. 

Zygoma.  The  cavity  under  the  zygomatic  process  of  the  tern* 
poral  bones;  from  £oya$  a yoke. 


VOL.  II. 


3 1 


' 


■ ( • 

. * ' . 


■ 


. ’ ill  : ‘ J 

i»  -v  *u  Wpi  • V - ••  «%1J§  . 

v 

. ' 

■ 


■ 

' 

. ■■■  v 

' 


if;:  V 


,';,v  , ^ 

. 

■ 


INDEX 


A. 

Abdomen 

Abernethy,  Mr.  statement  by  him  in  the  London 
Philosophical  Transactions 
case  of  termination  of  the  vena 
portarum  in  the  vena  cava  be- 
low the  liver 

description  by,  of  the  mesenteric 
gland  of  the  whale  ; 

Absorbent  vessels 

of  the  lower  extremities 
of  the  head  and  neck 
of  the  abdomen  and  thorax 
of  the  arm  and  upper  part  of 
the  trunk 

Acetabulum 

Accessory  nerve  of  Willis  .... 

Acini  of  the  liver  

Adhesion  of  the  lungs  to  the  thorax 

Adipose  artery 

membrane 

Adjustment  of  the  center  of  gravity 
Alphabetical  arrangement  of  the  muscles 

Alveolar  artery 

Anastomotic  artery 

Andre,  M.  St 

Animal  motion,  question  respecting 

Aorta 

table  of  the,  exhibiting  the  distribution 
of  its  branches  .... 


Vol.  I. 
Page 


104 


401 

307: 

265 


413 

168 


Vol.  II. 
Page 
83 


140 

381 
377 

382 
126 

397 

398 

346 

133 

73 

283 


250 

295 


238 

300 


436  INDESL 

Voi.  r. 
Page 

Appearance  of  the  caecum  and  colon 

Appendix  of  the  diaphragm  . . . 210 

Aqueducts  of  the  ear 395 

Aqueous  humour  .....  370 

Arbor  vitae  s 332 

Arm,  bones  of  the  .....  115 

nerves  of  the 

Arrangement  of  the  jejunum  and  ileon 


Arteries,  general  account  of  their  distribution 


Articulations,  general  account  of  „ . . 273 

Astragalus 151 

articulation  of  the  . . . 295 

Auditory  nerve 394 

Auricular  artery  . ..... 

Axillary  artery  ...... 

vein  ...... 

Azygos,  vena  ...... 


Bo 

Baillie,  Dr.  ...... 

Ball  of  the  eye  ......  349  . 

Barclay,  Dr. 

Basilar  artery  ..... 

Basilic  vein 

Basis  of  the  cranium 62  . 

brain  ......  333  . 

Eaynham,  Dr.  of  Virginia,  his  method  of  in- 
jecting the  rete  mucosum  ....  408  . 

Bell,  C 371  . 

Bell,  John,  observation  of  ... 

Berlin,  royal  acinic  my  of  sciences  of  . 415  . 


Berzelius,  professor  of  chemistry  at  Stockholm, 
his  experiment  on  secretion 
Bichat,  M.  opinion  embraced  by,  respecting 

the  extent  of  the  retina  . . 364  . 

of  the  pores  of  the  cuticle  . . 416  . 

doubts  of,  the  existence  of  the  rete 
mucosum  in  the  tongue 


Voi.  H. 
Page 
119 


353 

116 

238 


247 

264 

311 

304 


77 

263 

261 

311 


141 


422 


2 i 


INDEX. 

Vol.  I. 
Page 

437 

Vol.  II. 
Page 

Bichat,  M.  his  solution  of  a problem 

74 

doubts  of,  respecting  the  muscula- 

rity  of  arteries 

230 

on  the  structure  of  arteries 

230 

Biliary  duct  

140 

Biliary  and  pancreatic  ducts,  orifices  of  . . 

114 

Bile 

142 

Bladder,  gall 

140 

urinary 

1$4 

Blood  ........ 

409 

colouring  matter  of  the 

412 

Bloodvessels  in  general  .... 

224 

of  the  tongue  .... 

23 

of  the  abdomen 

88 

Boerhaave,  K.  experiments  of 

402 

Bones,  structure  of 

i 

formation  of 

5 

terms  used  in  the  description  of 

6 

Bostock,  Dr. 

71 

his  assertion  respecting  th^e  blood 

411 

Boyer,  M.  ...... 

169 

Brachial  plexus  of  nerves  .... 

352 

construction  of  the 

353 

Brande,  Mr.  on  the  serum  of  the  blood 

411 

his  chemical  researches  respect- 

ing  the  blood 

416 

Brain,  basis  of 

333 

commissures  of  .... 

329 

middle  artery  of  .... 

257 

nerves  of ' 

333 

f|itish  anatomists  on  the  spleen  . 

153 

Brodie  on  the  source  of  motion  in  the  heart 

82 

Bronchi*,  black  glands  on  ... 

64 

Bronchial  artery 

274 

Bucquet,  M.  

415 

Buisson,  M.  

Burs*  mucosae 

275.  302 

♦ 

345 

438  INDEX. 


Vol.  1. 
Page 

Vol.  II. 
Page 

c. 

Caecum ; 

119 

position  of 

120 

Camper 

220 

Canals,  semicircular  .... 

392 

Capsular  arteries  .... 

283 

veins 

315 

Cardiac  plexus 

372 

Carlyle,  Dr.  

163 

Carotid  arteries 

240 

Carpus . 

125 

Cauda  equina 

340 

Cavallo,  Tiberius  . . 

412 

Cavities  of  the  nose  .... 

56 

Cavity  of  the  cranium  .... 

59 

tympanum 

379 

Cellular  membrane  .... 

398 

Cerebellum 

332 

Cerebrum 

321 

Cephalic  vein 

311 

Change  of  colour  in  negroes,  instance  of 

410 

Changes  of  the  rete  mucosum  in  white 

persons 

411 

Change  of  position  in  the  stomach 

Choctaw  Indians,  custom  of 

66 

Chorda  Tympani  .... 

386 

Choroid  coat 

353 

Ciliary  ligament 

355 

processes  .... 

360 

Circulation  in  the  placenta,  objects  of  the 

222 

Circumflex  artery  of  the  os  ilium 

292 

vein 

318 

Clavicle 

109 

Coat  of  the  liver 

138 

Cochlea.  ...... 

390 

Colon,  structure  of  .... 

120 

valve  of  the  .... 

122 

Cooper,  Mr.  Astley  .... 

83 

Cornea  ... 

351 

INDEX. 

Coronary  veins 

Vol.  I. 
Page 

439 

Vol.  II. 
Page 
302 

Corpora  albicantia  of  Willis 

334  . 

Corpora  cavernosa  : 

187 

cells  of  the 

188 

lutea  . . . . 

211 

Corpus  spongiosum 

190 

structure  of 

191 

Corpsucula  Arantii 

55 

Crassamentum 

411 

Cremaster  muscle  ..... 

176 

Cricoid  cartilage 

51 

Cruikshank,  Mr.  Wm.  his  opinion  respecting 
the  vessels  between  the  rete 

mucosum  and  cutis  . . 406, 409  . 

his  experiments  favourable  to  the 
idea  of  the  motions  of  the  heart 

being  independent  of  the  brain 

• 

8© 

his  ideas  relative  to  the  origin  of 

the  lacteals 

. 109,  S79 

his  description  of  the  appearance  of 

the  absorbents  of  the  kidney 

387 

his  injection  of  the  absorbents  of 

the  pancreas 

393 

his  demonstration  of  those  of  the 

hmgs 

396 

Crural  nerve 

361 

Crystalline  lens 

368  . 

Cubital  nerves 

. . 

349 

Currie,  Dr.  (of  Liverpool)  .... 

. 

401 

Cuticle  

413  . 

Cuticle,  pores  of 

414  . 

peculiar  permeability  of  . 

415  . 

- • 

separation  of  the  .... 

418  . 

chemical  qualities  of  the 

419  . 

Cuvier,  M.  his  opinion  respecting  the  vascular 
convolutions  of  the  corpus  spongi- 

osum  of  the  horse 

. 

199 

440 


INDEX. 


D. 


Vol.  I. 
Page 


Vol.  II. 
Page 


Daingerfield,  Dr.  his  experiments  . ...  401 

Delile,  M his  memoir  on  the  organs  of  absorp- 
tion in  mammiferous  animals  . ...  403 

Desault,  M.  his  ideas  respecting  the  structure 

of  the  spleen  ....  ...  152 

his  experiment  respecting  the  frontal 
sinus  ......  ...  13 

Diaphragm  .......  210  . . . 

nerves  of  the  ....  ...  351 

Digital  arteries ...  272 

Dorsal  nerves ...  357 

Dorsey,  Dr.  John  S ...  73 

Duct,  thoracic ...  393 

hepatic ...  136 

cystic ...  140 

Ductus  venosus  ...  221 

Duodenum  ...  313 

Dupuytren,  M.  inference  from  his  statement  in 
a volume  of  the  proceedings  of  the 
National  Institute,  respecting  the 

nerves  of  the  lungs  ...  ...  73 

Dura  mater  ......  $15  • • - 


Ear  . ... 

E. 

374  . . 

bones  of  the 

383  . . 

Ellis  on  respiration 

Elbow,  articulation  of  the 

284  ..... 

Emulgent  arteries 

veins 

Epidermis 

413  . . 

Epididymis  .... 

Epigastric  artery 

vein 

Epiglottis  . 

Eustachian  tube 

382  . . 

External  pudic  arteries 

. 

71 

283 

315 

179 

279 

318 

30 


292 


INDEX. 

441 

Vol.  I. 

VoL  II. 

Page 

Page 

External  iliac  arteries 

291 

iliac  veins  ..... 

318 

Eye,  description  of  the  orbit  of  the 

54  . . . 

parts  auxiliary  to  the 

343  • . . . 

ball  of  the 

349  ..  . 

humours  of  the 

365  ..  . 

dissection  of  the  .... 

371  ..  . 

effect  of  the  solution  of  nitrate  ©f  silver 
on  the  hyaloid  coat  of  the 

373  ..  . 

F. 


Face 

Facial  artery 

33 

224 

Fauces,  isthmus  of  the 

29 

Fallopian  tubes,  structure  of  the 

209 

Falconer,  Mr.  on  the  spleen 
Falx 

318 

153 

Femoral  artery 

292 

vein 

318 

Fcetus,  head  of 

67 

thorax  of 

69 

trunk  of 

106 

extremities  of 

160 

Fibula 

145 

Fimbriae  . . 

Fingers 

136 

210 

articulation  of  the 

. 

288 

Foot 

Fontana  Abbe 

149 

80 

on  the  structure  of  the  nerves 
on  the  colour  of  the  blood 

158 

413 

Foramen  caecum 

23 

lacerum  . 

63 

ovale 

53 

thyroideum 

103 

Forearm 

120 

interosseous  ligament  of  the  . 

297 

Vol.  II.  3 K 


442 


INDEX. 


Vol.  I.  Vol.  II. 

Page  Page 

Fornix  . . . . . . 326  . . . 

Fossa  ovalis  . . . . . 79  . . • 

Fourcroy,  M.  . . . ...  401 

French  anatomists,  their  peculiar  opinions 
respecting  the  course  of  the  blood  in  the 

foetus  . . . . 75 

Fyfe,  Mr.  on  tie  villi  ....  , . . 110 

or 

Gall,  Dr.  . . . 338  . . . 

Ganglions  . . . . . ...  325 

Gastric  liquor  . . . . ...  103 

Gavard,  M.  proposition  of  . . . . ; 118 

Generation,  female  organs  of  . . ...  200 

male  organs  of  . . ...  173 

Glands  inguinal  . . . . ...  384 

' Glands  on  the  bronchia:  . . . ...  64 

of  the  mesentery  . . . ...  118 

of  the  neck  . . . . ...  347 

Glandulse  Buccales  . . . » ...  15 

Brunneri  . . . . ...  107 

Peyeri  . . . . ...  107 

Molares  . . . . ...  257 

Renales  . . . . ...  156 

Gluteal  artery  . . . . ...  289 

Goodwin,  Dr.  his  explanation  of  the  effects  of 

venous  blood  on  the  heart  ...  74 

Graff  De,  his  successful  investigation  of  the 

testicle  . . . . . ...  182 

Grew,  Dr.  .....  414  . . . 


H. 


Haighton,  Mr.  a dissection  of  the  ear  record 


ed  by 

397  . . 

essay  of  . . . 

. . 

Haller,  M.  on  muscular  fibres 

163  . . 

* , 

remarkable  sentiment  of 

42 

INDEX.  443 

Vol.  L Vol.  II. 

Page  Page 

Haller,  M.  inclined  to  the  opinion  of  Ruysch  on 

the  spleen  ....  ...  152 

a cavity  in  the  glandule  renales  fre- 
quently found  by  ...  157 

his  publication  in  the  Philosophical 
Transactions  of  London  . ...  182 

on  the  testicles  of  the  foetus  . ...  220 

his  great  attention  to  the  arterial 

system ...  263 

his  observations  on  the  absorbent 

vessels ...  378 

Hand 125  ..  . 

Hatchet,  Mr.  Charles ...  411 

Heart,  description  of  the  ....  ...  50 

Hepatic  artery ...  278 

veins ...  314 

Hewson,  Mr.  William,  on  the  Villi  . ...  109 

his  opinion  respecting  the 
spleen  ....  ...  153 

on  serum  ....  ...  410 

on  the  crassamentum  . ...  412 

on  the  colour  of  the  blood  . . . 414 

on  the  structure  of  glands  . . . 420 

Hewson,  Dr.  T.  T . his  experiments  on  the  blood  . . . 412 

Home,  Mr.  Croonian  lecture  of  168  . . . 

his  assertion  respecting  the  mem- 

brana  tympani  . . . 381  . . . 

confirmation  of  the  account  of  the 

vesicles  in  the  spleen  . ...  154 

his  questions  relative  to  the  blood  . . . 422 

Hottentots,  female,  peculiarity  of  the  . ...  217 

Humboldt,  M.  on  the  experiments  of  Legallois  ...  81 

Humeral  artery ...  267 

Hungarians,  peculiarity  of  the  ...  ...  220 

Hunter,  Dr.  William 401  ...  73 

opinion  of,  on  the  villi  . ...  109 

his  opinion  respecting  the  struc- 
ture of  glands  . . ...  420 

belief  respecting  a part  in  glands 
not  injected  in  his  preparations  . . . 420 


444* 


INDEX. 


Vol.  I. 
Page 


Vol.  II. 
Page 


Hunter,  Dr.  William,  his  idea  of  fluids  which 
appear  in  the  various  cavi- 


ties  of  the  body 

. 

421 

Hunter,  Mr.  John  

• . 

103, 

185 

his  opinion  respecting1  the  vascular 
structure  of  the  corpus  spongio- 

sum  urethrae  .... 

. . 

199 

fact  established  by  experiments  of 

403 

on  the  structure  of  arteries 

229 

on  the  colour  of  the  blood 

. . 

413 

Hypogastric  artery 

. . 

286 

vein  ..... 

3ir 

i-J. 

Iliac  arteries 

285 

veins  . ...... 

317 

Injected  preparations,  examination  of  . 

273 

Instances  of  peculiar  arrangement  of  veins 

320 

Intercostal  arteries  ..... 

275 

veins  

305 

Interosseal  artery 

Internal  basis  of  the  cranium 

59  . . 

271 

Intestines 

106 

division  of 

Iris 

356  . . 

111 

Ischiatic  artery 

289 

Jejunum  and  ileon 

114 

Jones,  Dr 

230 

Jugular  veins,  internal  .... 

307 

external  .... 

309 

Jussieu,  M.  account  by,  of  a female  born  with- 

out  a tongue  .... 

28 

K. 

Kidneys 

158 

cortical  and  tubular  portions  of  the 

. . 

161 

nerves,  lymphatics,  and  coat  of  the 

. 

162 

absorbents  of  the  .... 

387 

* INDEX.  445 

Voi.  i.  Voi.  n. 

Page  Page 

Klapp,  Dr.  .......  ...  401 

Knee,  articulation  of  the  ....  291  . . . 

L. 

Labia  externa  ......  ...  201 

Labyrinth 388  . . . 

contents  of  the  ....  393  . . . 

functions  of  the  different  parts  of  396  . . . 

Laennec,  M. ...  138 

Lachrymal  gland  346  . . . 

sac 347  . . . 

Lacteals ...  388 

Larynx  ...  31 

Legallois,  M.  experiments  of,  on  the  source  of 

the  motion  of  the  heart  . ...  80 

Lieberkuhn,  M ...  108 

Lieutaud,  M. ...  169 

Ligaments 297  . . . 

Liver ...  129 

absorbents  of  the  ....  ...  391 

Lumbar  arteries ...  285 

veins ...  316 

nerves ...  359 

plexus ...  360 

Lungs,  ...  65 

structure  of ...  67 

absorbents  of ...  395 

Lymphatics  in  the  spermatic  cord  . ...  177 

of  the  uterus  ....  ...  213 


M. 

Magendie,  M.  experiments  of,  on  the  organs  of 
absorption  in  mammiferous 


'animals  ...  ...  403 

Malformation,  cases  of  ....  ...  72 

Malpighi,  M.  on  the  structure  of  the  spleen  . ' . . 149 

on  the  structure  of  glands  . ...  419 

Mammary  artery  ...  359 


446  INDEX. 

Vol.  I. 

Vol.  II. 

Page 

Page 

Marcet,  Dr.  

73 

Mascagni,  M.  on  the  villi  .... 

110 

on  the  absorbents  of  the  kidney 

387 

assertion  of,  in  his  great  work 

on  the  absorbent  system 

421 

his  ideas  respecting  the  structure 

of  glands  .... 

420 

Mastoid  cells 

382  ..  . 

Maxilla  inferior  ...... 

44  . . . 

Maxillary  arteries 

244 

nerves  ..... 

. .'  . 

338 

Meatus  Auditorius  Externus 

377  ..  • 

Internus 

392  ..  • 

Meckle,  Professor,  his  opinion  respecting  the 

outlets  of  perspiration  . 

415  i . . 

on  the  nerves  of  the  face 

342 

Mediastinum ... 

Median  nerve 

354 

vein ... 

Meibomus,  glands  of 

346  ..  . 

Membrane,  adipose 

410  ..  . 

Schneiderian  .... 

5 . . . 

extent  of 

9 . . . 

distribution  of  : 

10  . . . 

Membrana  tympani 

380  ..  . 

observations  on  the 

387  ..  . 

Menghini,  Vincentius,  his  experiments  tend- 
ing to  establish  the  opinion,  that  the  colour 

of  the  blood  depends  upon  iron 

414 

Mesentery 

116  ..  . 

construction  of  ... 

117  ..  . 

root  of 

118  ..  . 

Mesenteric  artery 

282 

vein 

315 

Metacarpus  

131  ..  . 

Metatarsus 

156  ..  . 

Middle  hemorrhoidal  vein  .... 

288 

sacral  vein 

316 

Monro,  Dr.  on  the  Burse  Mucose 

275  ..  . 

on  the  iris  .... 

359  ..  . 

INDEX. 

Vol.  I. 
Page 

447 

Voi.  n. 
Page 

Monro,  Dr.  opinion  of,  respecting  the  extent  of 

the  retina  .... 

364 

his  opinion  respecting  the  villi 

109 

observation  of,  on  the  epididymis 

182 

Morgagni,  M.  ventricle  of  . 

34 

Motion,  muscular,  phenomena  of 

166 

of  the  skeleton  .... 

167 

Mouth  

14 

internal  surface  of  the 

15 

Mucus  of  the  nose 

13 

of  the  bladder  .... 

168 

Mussey,  Dr.  . .... 

401 

Muscles,  alphabetical  arrangement  of 

265 

N. 

Nails 

419 

Neck,  arteries  of  the  .... 

263 

absorbents  of  the  .... 

397 

muscles  of  the 

219 

Nerves,  general  account  of  ... 

323 

Nichols,  Dr.  F. 

153 

Nose 

1 

cavities  of  the 

56 

5 

nerves  of  

8 

sinuses  of  

13 

o. 

Obturator  artery 

238 

Occipital  artery  

246 

Oesophagus  

95 

Olfactory  nerve 

328 

Omentum,  origin  and  arrangement  of 

127 

varieties  in  the  appearance  of 

128 

Ophthalmic  artery 

254 

nerve  

332 

Ovaries  ....... 

-« 

210 

Os  frontis 

14 

Ossa  pari’etalia  

17 

448 


INDEX. 


Ossa  temporum 

Vol.  I. 
Page 

18 

Vol.  II 
Page 

Os  occipitis  .... 

22  . 

Os  ethmoides 

24  . 

Os  sphenoides 

28  . 

Ossa  maxillaria  «uperiora 

. 

34  . 

Ossa  nasi  .... 

37  . 

Ossa  unguis 

38  . 

Ossa  malarum 

39  . 

Ossa  palati  .... 

40  . 

Ossa  spongiosa 

43  . 

Os  hyoides 

52  . 

Os  sacrum  .... 

84  . 

Os  coccygis 

86  . 

Os  ilium  .... 

99  . 

Os  ischium 

100  . 

Os  pubis  .... 

102  . 

Os  humeri 

115  . 

Os  femoris  . 

139  . 

Os  calcis  .... 

151  . 

Os  naviculare 

153  . 

Os  cuboides 

153  . 

Os  cuneiforme 

154  . 

Palpebrae  .... 

P. 

344  . 

Pancreas  .... 

144 

Pancreatic  duct 

. 

145 

Pancreas  enlarged,  symptoms  of 

146 

Papilla:  of  the  tongue 

22 

ParVagum  .... 

343 

Parotid  gland  . . . 

25 

Patella  ..... 

147  . 

Pears,  Mr.  C.  account  by,  of  a woman  in  whom 
the  ovaria  were  deficient 

216 

Peculiarity  of  the  liver 

139 

Pelvis 

98  . 

ligaments  of  the 

299  . 

absorbents  of  the 

387 

INDEX. 


Perforating  arteries 
Pericardium  . 

Peritoneum 

Periosteum  . . ' . 

Peroneal  artery 
nerve 

Pharyngeal  artery,  inferior 
Pharynx,  structure  of  the 
Phrenic  artery 

vein  . „ • . 

Physicfc,  Dr.  his  opinion  respecti 
of  the  cornea 
Pia  mater  . 

Pineal  gland 

Pleura,  arrangement  of  the 
Plexuses  of  nerves 
Plexus  choroides  . 

Pomum  Adami 
Popliteal  artery 
Pores  of  the  cutis  vera 
Portarum  vena 
Portio  Dura 

Posterior  iliac  artery  : 

Poupart’s  ligament,  method  of  preparin 
examination 
Priestley,  Dr.  . . 

Primitive  iliac  arteries 
veins 

Provencal,  Dr.  J.  M. 

Ptidic  artery 

Pulmonary  arteries  and  veins 
plexus 

Puncta  Lachrymalis 
Pylorus  .... 


Vol.  I. 
Page 


it  for 


352 

sir 

330 


327 


4C5 


200 


347 


Q. 

Questions,  respecting  perspiration  , . 415  . 

the  structure  of  the  spleen 
Questions  of  Mr.  Home  ... 

Vol.  II.  3 L 


44-9 

Vol.  IL 
Page 

294. 

49 

91 

298 

365 

245 

38 

277 

313 


45 

325 

31 
29  S 

1 35 
339 
289 


71 
287 
316 
73 
290 
60,  321 
345 

104 


154 

422 


450 


INDEX. 


Vol.  I.  Vol.  II. 

Page  Page 

• R. 

Radial  artery ...  269 

nerve ...  356 

Radius 122  • . . 

Reticular  membrane 401  . . . 

Reaumur,  M. ...  103 

Rectum,  position  and  structure  of  . . ...  124 

Renal  arteries ...  283 

Reproduction  of  nerves  ....  ...  32 7 

Rete  mucosum 408  . . . 

Retina  ; 363  . . . 

Ribs  .......  . 88  . . . 

Ridley,  circular  sinus  of  ...  320  . . . 

Rima  glottidis ...  35 

Rivinus,  professor,  erroneous  opinion  of  . 381  . . . 

Rolland,  M-  ...  28 

Rousseau,  Dr. ...  401 

Rush,  Dr.  James  ...  128 

Ruysch,  M.  355  . . . 

preparation  of  ...  ...  15 

on  the  structure  of  the  spleen  . ...  150 

his  opinion  on  the  structure  of 

glands ...  419 

s. 

Sabatier,  M.  idea  of,  respecting  the  bloodvessels 

and  the  colour  of  muscles  . 164  . . . 

theory  of,  relative  to  the  foetal 

circulation  . . . ...  75 

observation  of,  on  the  stomach  . ...  105 

supposition  of,  respecting  the  rectum  . . . 124 

Sacral  artery  . . . . ...  235 

Saliva ...  27 

Salivary  glands  . . . . ...  25 

Scapula  .....  110  . . . 

articulation  of  282  . . . 

Sciatic  nerve  . . . . . • . 364 

plexus 


363 


INDEX. 

451 

Vol.  L 

Vol.  IL 

Page 

Page 

Serum  ; 

410 

Scheele,  Mr.  «... 

71 

Schneider,  Dr  Conrad 

5 

Sheldon,  Mr.  John  .... 

109 

Shippen,  Dr.  J.  G. 

118 

Sims,  Dr.  ..... 

38 7 . . . 

Skin,  vicarious  affection  of  the  . . 

422  ..  . 

Sone,  De  La,  opinion  of,  on  the  spleen 

151 

Soemmering,  interesting  discovery  of 

364  . . . 

idea  of,  respecting  the  papilhe  of 

the  tongue 

22- 

opinion  of,  on  the  villi 

110 

statement  of,  respecting  injections 

of  absorbent  vessels 

380 

Smelling,  function  of  ... 

12 

Spallanzani,  Abbe  .... 

71 

dissertation  of 

103 

Spheno-Palatine  artery  . 

251 

Spleen,  general  account  of 

146 

absorbents  of  ... 

392 

Spinal  marrow  .... 

339  ..  . 

arteries  of  the 

341  . . . 

veins  of  the  . 

342  ..  . 

Spermatic  arteries  .... 

284 

veins  .... 

316 

Splenic  artery  .... 

279 

Stewart,  Dr  J.  Bradner 

401 

Stiles,  Sir  F.  H E. 

413 

Stomach,  general  view  of  the  , 

97 

absorbents  of 

390 

Structure  of  ganglions 

320 

Structure  of  glands  .... 

417 

Subclavian  arteries  - 

258 

veins  ... 

314 

Superior  mesenteric  artery 

280 

vein 

315 

Superior  vena  cava  .... 

303 

Sympathetic  nerve  .... 

36  r 

452  - INDEX. 

VoI.I. 

S»*gv 

Vet.  a. 
Page 

T. 

Tears  ...  ... 

347 

Teeth  ..... 

47 

Temporal  artery  .... 

251 

Thebesius,  a German  Professor,  assertion  of 

' 5* 

Thigh  ..... 

138 

Thoracic  duct  .... 

393 

Thorax  ..... 

44 

Throat  ..... 

29 

Thymus  gland  .... 

69 

Thyroid  artery,  superior 

243 

inferior 

260 

Tongue  ..... 

18 

Torre,  Father  de  la 

413 

Trachea  ..... 

6£ 

Tunica  Arachnoidea  .... 

317 

Tunica  Conjunctiva  .... 

345 

Tunica  Sclerotica  .... 

350 

Tunica  Choroides  .... 

353 

Tunica  Hyaloidea  .... 

366 

fluid  in  the 

367 

Tympanum,  cavity  of  the 

380 

foramina  and  protuberances  of  the 

383 

u. 

Umbilical  vessels  .... 

226 

Ulna  ...... 

120 

Ulnar  artery  ..... 

271 

nerve  ..... 

355 

Urine  ..... 

171 

Uterine  artery  .... 

287 

Uterus  ..... 

205 

V. 

...  53 


Valve  of  Eustachius 
Vieussens 

Valvulx  Tricuspides 


333 


53 


INDEX,  • 

1TgI»  3% 

Valvulae  Mitrales  .... 
Semilunarea 

Vas  Deferens  .... 

Vauquelin,  M.  .... 

Vena  azygos  ..... 

Vena  cava,  superior  .... 

inferior  .... 


Vena  Galeni  .....  331 

Vena  portarum  . 

Venae  vesicales  .... 

Ventricles  of  the  brain  . . . 324 

Veins,  particular  distribution  of 
Veins  of  the  heart  .... 

Vertebrae,  connexion  of,  with  the  head  . 276 

articulation  of,  with  each  other  277 

Vertebrae,  true  ....  70 

Vertebrae,  false  ....  84 

Vertebral  artery  .... 

vein 

Vesalius,  M.  his  method  of  examining  the 

brain  ....  327 

Vesication,  causes  of  ...  417 

Vestibule  .....  389 

Vidius,  professor,  reputed  discoverer  of  the 

pterygoid  foramen  . . 33 

Vieussens,  assertion  of 

Vitreous  humour  ....  365 


w. 

Wells,  Dr. 

Wollaston,  Mr.  .... 

Winslow  . . . : . 75 

Wilson,  James  Esq.  ....  206 

Willis,  accessory  nerve  of 

Wrist,  articulation  of  . , . 285 


453 

Yoi.  n. 
Page 
56 
56 
183 
415 
304 
303 

313 

314 
317 

SOI 

302 


260 

306 


58 


415 

422 


346 


ERRATA. 


VOLUME  I. 

Page  74... .last  line,  for  cervical  read  vertebral. 

187. . .1st  line,  for  palati  read  palate. 

199..  -.6th  from  below,  for  their  facia  read  thin  facia. 

223.. . .4th  line,  for  first  vertebra  of  the  neck  read  vertebrae  of  the  neck. 

265.. ..  for  cuculearis  read  cucullaris. 

277—.17th  line,  for  bones  of  the  condyles  read  bases  of  the  condyles. 

335..  ..1st  line,  for  Pons  Variolii  read  Pons  Varolii. 

344.. ..6th  line,  for  orbicularis  muscle,  {see  page  171),  in  the  upper  eye- 

lid:) read  orbicularis  muscle  {see  page  171.)  in  the  upper  eyelid: 

352.. . .10th  line,  for  charged  read  changed. 

357-. ..12th  line,  for  plain  read  plane. 

2,  10,  352,  366,  367,  369,  for  lamen  read  lamina — for  lamina  read 
lamince. 

389..  ..15th  line,  for  solid  read  hard. 

398..  ..3d  line,  for  these  read  them. 

409..  ..12th  line,  for  as  injection  read  as  an  injection. 

422.. .  (title)  for  vicarious  connexion  read  vicarious  affections  of  the  skin, 

VOLUME  II. 

Page  96.. ..11th  line,  for  found  read  formed. 

156..  ..for  Chapter  VI.  read  Chapter  IV. 

272.. ..14th  line,  from  below,  for  radial  read  ulnar. 

339..  ..17th  line,  for  Portio  Dura  read  Portia  Mollis. 


■ 


X 


* 


- 


I 

Wistar 
v.  2 
1814 


